# Adding Red and Blue LEDs



## Quizcat

Is there a rule of thumb, similiar to the "Watts per Gallon" for 6500K white light, which I realize is an antiquated way of estimating light required for a planted tank, which can be applied when estimating how many RED and Blue Led light strips to add to an existing light fixture? I want to add some RED and BLUE LED light strips to an existing light fixture, and not sure how many strips to add in order to get the optimum growth effect from the Red and Blue LEDs upon the plants. I am considering using SMD5050 light strips, which generate about .36 watts per gallon, but I'm not sure that the "watts per gallon" method correlates for RED and BLUE light, in the same way it does for 6500K white light.


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## TropTrea

The bad part of the watts per Gallon and especialy with LED's is the Wide range of light emmitted by the LED's between the different manufacturers and series of LED's. 

As an example you can get a three WATT LED that will put out 600 lumens of light when run at 3 Watts and another Manufacturers LED at 3 Watts might put out only 180 Lumns of light. Both having the virtual same light spectrum. 

Now when you start looking at red a blue LED's you have some added issues. First off the Light spectrum is very narrow and one blue led will not cover the entire part of the the blue photosynthesis range. The same is true for the reds so you now probably going to use two different blue LED's and probably 2 different red LED's. Next with these being so efficient but narrow spectrum means that they are very intense in that spectrum. So it will not tank many blue LEDs to push the K temperature of the liughting up or many red LED's to give you a pink tank.

I prefer balancing between Cool Whites that have a strong blue spectrum and the neutral or warm whites that have a strong red spectrum. Rather than depending on Blue and RED LED's. Yes pushing the blues with a couple Blue LED's is not objectionable to most but be careful of going to blue. I would not use more than one colored LED per 3 White LED's at the most. If you want to add both red and yellow then it be closer to 1 red, 1 blue, and 6 White LED's.


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## Quizcat

Hey thanks, that is the guidance I am looking for. So, it seems that the ratio should be around 6:1 on white to red/blue. I noticed during my search of what's available for purchase, that on some of the SMD5050 light strips you can actually order them with a ratio of 4:1, 5:1, 7:1, and 8:1, white to red/blue. It sounds like I could select the 5:1 or the 7:1 ratio, and be pretty close the ratio you advised without having to cut the strips apart, and deal with all the soldering, etc...But, as you say, the issue will be the actual performance of the LEDs with respect to PUR value as it relates to the proper amount of light for the plants.

I'm considering installing 5 x 6400K 10 Watt LED emitters in a fixture to achieve the full range of light needed for the plants, then install some red and blue LEDs just for viewing sake, to bring the glow colors out on my Glowfish.

But, if I wanted to use the strips only, omitting the 10 Watt LEDs, I have space to fit about 8 x 24" long strips of SMD 5050 RGBWW LED Light Strips (Red, Green, Blue, Warm White, Cool White (6400K). The SMD 5050 LED strips can generate variations of light, various hues, including violets, etc...). There are 60 LEDs per meter (39.37"). The strips have Warm White/RED/BLUE/GREEN within some of the LEDs, then there are also separate LEDS that are the same size that are COOL White (6400K) only, very bright, and they can be activated seperately via the remote control. Theoretically, that number of strips should produce around 70 watts of light with all LEDs at full intensity, assuming that the wattage they're rated at actually translates into a good PUR value in the aquarium, which is a 20 gallon standard (tall) tank.

Using the old method of watts/gallon, that would result in about 3.5 watts per gallon of light, just using the SMD505 strips alone, which should be sufficient for plants that require low to medium levels of light. I realize that watts/gallon isn't the best way to determine plant lighting requirements, but I don't have a PUR meter to measure the actual performance of light in the aquarium, so "plants per gallon" with have to do.

Then, I figured that if I wanted to add even more Cool White (6400K) light, I might want to omit an LED strip or two, use maybe 6 x LED strips instead of 8 x LED strips x 24" long, making room (5) 10 Watt LED Cool White (6400K) LED Emitters, spaced out the full length of the fixture (24"), to enhance whatever amounts of white light (6400K) might be needed by the plants if I just wanted to run them indepedently of the colored LED strips.

Under those terms, the fixture would be capable of delivering a total of about 100 watts of light, if both the 10 Watt emitters, and (6) x 24" of RGBWW strip lights are activated simultaneously. I've read that LED lights actually deliver more PUR to tanks than most other kinds of light sources, so the PUR value of the LED light might even be greater than 100 watts of light with everything activated. But, conceptually, using watts/gallon, if the 100 watts of light were activated at the same time, then that would give me about 5 watts per gallon (20 gallon tank), sufficient even for plants requiring even higher levels of light.

By combining the (5) 10 Watt Cool White Light Emitters (6400K), with the SMD505 RGBWW LED strips, I should be able to deliver the sufficient amount of light the plants need for robust growth, while also being able to activate the LED light strips independent of the LED Emitters for times when I just want enhanced color for viewing.

Do these conclusions make sense, and is there anywhere I am going wrong with my conclusions before I begin building this conceptual design? I appreciate any and all advice...



TropTrea said:


> I would not use more than one colored LED per 3 White LED's at the most. If you want to add both red and yellow then it be closer to 1 red, 1 blue, and 6 White LED's.


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## TropTrea

I am using 10 Watt Emitters on my tanks which are DIY's. But I an only running each emitter at between 2 and 3 watts. If you go with 20 Watts of LED lighting using Quality Cree of Phillips emitters you will be in the high light range comparable to roughly more than 80 Watts of florescent lighting. 

The issue you run with on a small tank using high powered LED's is that you can color seperation of banding in the tank. If you want get into the high powered range using LED's on a 20 gallon I would look at using the 5 and or 10 watt emitters, but running them at a lower wattage. You could run 14 LED on a single circuit and if select the LED's correctly mix the colors. If I wanted to use 3 (colors) on a 24" tank I would look at something like 4 Blues, 4 Reds, and 4 Cool Whites on one driver then run 12 Neutral Whites on another driver. This would give you 24 emiters total.

The mixed channel would give you 
12 Watts with a 350 ma driver
24 Watts with a 700 ma driver
36 Watt with a 1040ma Driver

The cool whites would give you 
12 Watts with a 350 ma driver
24 Watts with a 700 ma driver
36 Watt with a 1040ma Driver
50 Watts with a 1400ma Driver

Initially I would run them both on 700 ma drivers. Which would give you a total of 48 Watts of light. Source your using quality LED's your light is probably close to 100 Watts of florescent light. You may want to cut it back so if you could replace either of the drivers with a 350 ma driver depending on how you like your tank looking. 

The other option is getting dimmable drivers. They are nice since you adjust the channels from 0 to max wattage as you see fit.

Another thought is you run the LED's 4 Red 8 NW on one channel and 4 Blue 8 CW on the other Channel. If you use dimmable drivers. But then both channels will be limited to a max of 36 Watts each. Noting that colored LED's are best run at 3 Watts each or less.


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## Quizcat

Well, that was another question on my mind, the amount of actual light that LED emitters can generate versus just standard light fixtures, like florescents. So, it sounds like LED Emitters of good quality put out about 4-6 times more light than a standard florescent fixture...per watt?...am I reading that correctly?

I am concerned that delivering 50 watts of 6400K from all 5 of the 10 Watt Emitters, at full power, is overkill. I suspect it would wash out any attempts to introduce the blues, reds, and greens. I think that was what you were meaning when you wrote about the banding issues, correct? So, knowing it's a 20 gallon tank, and if I wanted to do this as cheaply as possible, would it be adviseable to cut down on the number of 10 Watt Emitters, perhaps 2 or 3, and drive them to full capacity for the plants? Then, use some 3 watt LED emitters situated between the 10 watt emitters, perhaps maybe three or four each of the red, blue, and green 3 Watt Emitters spread out between say 3 x 10 watt emitters?

I have 5 x 10 watt LED emitters coming, but they're probably not CREE or Phillips...they're coming from Hong Kong, so...who knows.  They were really inexpensive, so it's no big deal if I opt to go a different direction, perhaps a great number of 3 watt cool white LEDs instead. I just figured I would get them on the "slow boat" sooner than later...

Lot of ways I can go with this, and I'm still not totally decided which would be the better scenario for my circumstances. I'm trying to kill two birds with one stone, and deliver sufficient light for low/medium range plants with respect to the plant's light requirements, while also addressing the visual effects....and I'm trying to do it cheaply as well.



TropTrea said:


> If you go with 20 Watts of LED lighting using Quality Cree of Phillips emitters you will be in the high light range comparable to roughly more than 80 Watts of florescent lighting.


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## TropTrea

The possibilities with LED's is considerable. Yes I would say 5 LED's running at 10 Watts each will probably be over kill on a 20 gallon tank. But what you can do is run them at a lower current so they are only using about 3 watts. Most will not even decrease the light output in half as they run more efficiently at lower wattage's. 

Then for your red and blues you can get 3 Watt LED's but only run them at 1 Watt each. Say you get 4 of each and alternate the Colors with the whites along the rail like this

W R B W R B W R B W R B W

This gives you 13 LED's in the line so you only have a little over a 2" spacing but at the reduced wattage may still get away with not having a fan to cool them. Total of 23 Watts which could be handled by a 1" X 2" alumnium channel 30" long.


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## Quizcat

Expanding on your idea of using the 10 Watt LEDs, permit me to run this by you...let me know what you think, ok?

I am considering omitting the 10 Watt and the 3 Watt LEDs, and going with 12 Watt, multi-color (red, blue, white (5700-8000K), green), CREE LEDs, and mounting each on a heat sink, which would further reduce my footprint, and take care of any heat disipation issues. If I used five of these multi-colored LEDs, that would give me a maximum of about 60 watts of available light in a 20 gallon tank, and I can adjust the colors down individually using a five channel controller.








Specifications:
Chip Series: Cree XM-L
Order Code: XMLCTW-A0-0000-00C3AAAA1
Emitted Color : RGBW/RGB White
PCB Board Color: White
Wavelength: Red 620~630nm, Green 520~535nm; Blue 450~465nm; White 5700~8000K
Product Voltage: Red 2.25~2.6V, Green 3.3~3.9V, Blue 3.1~3.7V, White 3.1~3.7V
Maximum Drive Current: 1A
Maximum Power: 12W
Max Luminous Flux: Red 87.4LM, Green 114LM, Blue 39.8LM, White 100LM
Viewing Angle: 130 Degree
PCB Diameter: 20mm








Heat Sink

Due to space limitations, 24" x 3-1/4", do you think I could mount about four or five of these CREE LEDs in a row, on heat sinks depicted above (if you think the LEDs will generate enough heat that heat sinks would be necessary). I could even add some 3-Watt Warm White (3000K) individual LEDs on PCB (heat sinked) pads, in between each of the 12 Watt LEDs, just in case I want to add-in some warm white (3000K) for visual effect?








IR LED Strip Light Controller

Above is the strip lighting controller that I've used in the past on strip lighting. The above controller supplies 12Vdc to strip lighting, and the controller will handle up to 72 Watts of strip lighting, and a maximum of 6 Amps. If I need to go with a more sophisticated controller than the strip light controller, which I like because of the small and simplistic foot print, are you aware of one in particular that you recommend, or are familiar with?



TropTrea said:


> The possibilities with LED's is considerable. Yes I would say 5 LED's running at 10 Watts each will probably be over kill on a 20 gallon tank. But what you can do is run them at a lower current so they are only using about 3 watts. Most will not even decrease the light output in half as they run more efficiently at lower wattage's.
> 
> Then for your red and blues you can get 3 Watt LED's but only run them at 1 Watt each. Say you get 4 of each and alternate the Colors with the whites along the rail like this
> 
> W R B W R B W R B W R B W
> 
> This gives you 13 LED's in the line so you only have a little over a 2" spacing but at the reduced wattage may still get away with not having a fan to cool them. Total of 23 Watts which could be handled by a 1" X 2" alumnium channel 30" long.


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## TropTrea

Quizcat said:


> Expanding on your idea of using the 10 Watt LEDs, permit me to run this by you...let me know what you think, ok?
> 
> I am considering omitting the 10 Watt and the 3 Watt LEDs, and going with 12 Watt, multi-color (red, blue, white (5700-8000K), green), CREE LEDs, and mounting each on a heat sink, which would further reduce my footprint, and take care of any heat disipation issues. If I used five of these multi-colored LEDs, that would give me a maximum of about 60 watts of available light in a 20 gallon tank, and I can adjust the colors down individually using a five channel controller.
> 
> View attachment 32778
> 
> Specifications:
> Chip Series: Cree XM-L
> Order Code: XMLCTW-A0-0000-00C3AAAA1
> Emitted Color : RGBW/RGB White
> PCB Board Color: White
> Wavelength: Red 620~630nm, Green 520~535nm; Blue 450~465nm; White 5700~8000K
> Product Voltage: Red 2.25~2.6V, Green 3.3~3.9V, Blue 3.1~3.7V, White 3.1~3.7V
> Maximum Drive Current: 1A
> Maximum Power: 12W
> Max Luminous Flux: Red 87.4LM, Green 114LM, Blue 39.8LM, White 100LM
> Viewing Angle: 130 Degree
> PCB Diameter: 20mm


First off you would only want to use the red, blue, and White LED's on this combination. So your talking about 9 Watts of final light max out of each of these Chips. The white is at 6,500K and as you add more red light you will lower the K level and as you add more Blue Light you will raise the K temperature.



Quizcat said:


> View attachment 32770
> 
> Heat Sink
> 
> Due to space limitations, 24" x 3-1/4", do you think I could mount about four or five of these CREE LEDs in a row, on heat sinks depicted above (if you think the LEDs will generate enough heat that heat sinks would be necessary). I could even add some 3-Watt Warm White (3000K) individual LEDs on PCB (heat sinked) pads, in between each of the 12 Watt LEDs, just in case I want to add-in some warm white (3000K) for visual effect?


These may work but not having dimensions or a spec sheet I'd only be guessing.

If you have 24" X 3" available you can go with a single piece of 3"X 1" Channel Aluminum that is 24" long. It should be able to handle the cooling for about 4 of these combination Chips. I think you would be more than happy with the light from 4 of these chip



Quizcat said:


> View attachment 32762
> 
> IR LED Strip Light Controller
> 
> Above is the strip lighting controller that I've used in the past on strip lighting. The above controller supplies 12Vdc to strip lighting, and the controller will handle up to 72 Watts of strip lighting, and a maximum of 6 Amps. If I need to go with a more sophisticated controller than the strip light controller, which I like because of the small and simplistic foot print, are you aware of one in particular that you recommend, or are familiar with?


You will need three channels of lighting. LED's of this quality should be driven by Current drivers rather than Voltage drivers. For driving these chips I would use the following.

White Channel Meanwell LPC-30-1040 which would be able to drive up to 10 of these chips at 3 Watts each.

Red Channel abd Blue Channel I would use LPF-16-D 12 which could handle 4 of your LED's. Please note you will need one for the red and one for your blue channel. You will be able to then adjust the amount of red light and blue light you want.


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## Quizcat

Thanks very much for the information and recommendations! I appreciate the help very much!

I may want to go ahead and use the green part of the LED just to vary the visual effects in the tank with another available color. So, I assume that if I wanted to include the green LED part of the chip, I would just get a third Meanwell Driver that will handle that.

I may try experimenting with the driver that I use for the strip lighting as well, but I am concerned that I don't over drive the LEDs in the process. The string of strip lights totals 72 watts of the same kind of LED chip, a four color (RED, GREEN, BLUE, WARM WHITE), then there are also separate Cool White LEDs, all in a strip, a total of 300 LEDs. Each one is installed on the strip in series, just as I will be doing with the CREE LEDs. I theorize that the strip light controller actually handles even a greater load than what I am planning for the CREE LEDs, since it will handle up to 72 watts in a strip, versus approximately 48-60 watts of CREE LEDs, depending on how many I use, 4 or 5.

The controller I use for the strip light supplies 12-24Vdc to an LED series circuit, and it has connections for RED, GREEN, BLUE, and WHITE LEDS within the controller. You provide your own 110 Volt AC transformer, which converts from AC to DC voltage to deliver 12-24Vdc to the LED circuit through the controller. But, I notice that the controller has a 2 Amp maximum current. I theorize that if I limit the current delivered by the transformer to the controller, perhaps 1 Amp from the transformer, since that's the maximum amount of current that can be delivered to the LEDs without over driving them, that I may be able to use the same controller that I've been using for the strip lighting without blowing out the CREE LEDs.

I haven't ordered the CREE LEDs yet, but I am expecting the off-brand Chinese Cool White LEDs to arrive from China in the next couple of weeks. If I fiind I'm able to drive them with the strip lighting controller, I'll let you know how my experiment comes out. If it works, the strip light controller only costs $6.95, including the remote control, plus the cost of a transformer, which is also pretty inexpensive, probably under $10.00, making the total cost for the strip light controller around $17.00, and it would handle all the LEDs from the one controller within a significantly smaller footprint. I am keeping my fingers crossed, as I am not an electrical engineer, and this theory of mine may be just that, a theory.



TropTrea said:


> First off you would only want to use the red, blue, and White LED's on this combination. So your talking about 9 Watts of final light max out of each of these Chips. The white is at 6,500K and as you add more red light you will lower the K level and as you add more Blue Light you will raise the K temperature.


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## TropTrea

Personally I think your better off getting simple AC to DC Current drivers. One simple Meanwell APC 12-700 driver can run 4 red LED's for only about $6.00. This gives you less component total that slowly builds up in cost, and you have the dependibility of long term proven parts. Note you can even bet APC 60- 1050 drivers to rum up to 14 LED's for only a few dollars more.


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## Quizcat

The APC-12-700 looks like a really good alternative. Thank you for making me aware of it!

I'm more and more skeptical that the strip light controller will work, but I'm still researching it through some electrical engineering contacts I have. But, what has me skeptical that it can be used without some major alterations to the series cirucuit is that I just learned that the strip lights may be assembled 3-5 LEDs per section, wired in series, then each section of 3-5 LEDs is combined together in Parallel to form a continuous strip of 300 LEDs that is 16.5' long.

I don't know how the strip light controller works with that kind of circuit, or if the circuit for the CREE Emitters can be duplicated to actually work with the strip light controller. I'm hoping to get an answer back from the masterminds that I know in the electrical engineering field. They'll probably tell me I'm completely off-base, but it's worth a try if I only have to add a resistor or two, etc...

The problem is, the Emitters have to be in series in order to use a 12Vdc driver because the Emitters are 3.1Vdc each. If you add them in series, that means I should have no more than 4 of them (3.1Vdc x 4 = 12.4 Vdc). But, in a Parallel circuit, they would only need 3.1Vdc, and a conventional power supply at 12Vdc would over drive them, probably blow them out. If I wanted to use (5) Emitters, then I would have to probably go with a controller that's rated at 12-24Vdc, something that delivers voltage based on what is being drawn by the complete circuit, something that doesn't over drive the circuit.

You had mentioned in a previous post that the driver should not be "voltage based," with respect to driving LED Emitters. So, just out of curiosity, I wanted to compare the light strip, and how it reacts with respect to voltage. Based on my meter readings on the strip, it seems that strips are voltage driven. When you increase or decrease the remote control for each of the colors in the strip, the voltage varys from about 4Vdc (Dimmer) to around 11.4Vdc (Brighter). The strip light is 12-24Vdc, so it provides voltage based on the draw of the devices in the strip light circuit.

I wouldn't have any issue with the cost of getting several of the APC controllers to handle all four colors of the LEDS. The footprint to drive all four colors is the only detractor. But, I may not have any alternative to having to have a relatively large footprint for the controller(s), if I want a full range of colors, technically speaking. And, as you mentioned, I might be just as well getting by with Red and/or Blue, and leaving well enough alone.

Thanks again! I'm going to check the APC controller out...



TropTrea said:


> Personally I think your better off getting simple AC to DC Current drivers. One simple Meanwell APC 12-700 driver can run 4 red LED's for only about $6.00. This gives you less component total that slowly builds up in cost, and you have the dependibility of long term proven parts. Note you can even bet APC 60- 1050 drivers to rum up to 14 LED's for only a few dollars more.


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## Quizcat

Here is the official determination from the electrical engineers as to why the strip light controller will not work for a circuit of individual LED Emitters...

"Those controllers work by passing through the voltage as a common anode, and typically have n-channel mosfets controlling the low side of each color channel. There is no current limiting in them. The led strips typically have 3 diodes plus a resistor in series (or 6 diodes for the 24v versions) per segment, and a multiple of those segments in parallel. The resistors provide the current limiting, and it's you that has to limit the size of the strip to 2 Amps.

The cree 10W diodes are similar, but are high amperage compared to the 0.06W leds in the led strips. Depending on the Cree led, it probably takes around 3 amps between the three (four?) Colors, and have no built-in current control. You must use a current controlled regulator source. Using resistors for these high amperages is impractical at best."

So, above is the reason why the APC or the Meanwell controllers are necessary for LED Emitters in a series circuit. In a series circuit, we can get away with using a 12Vdc controller, up to a certain point, in my case, a 12Vdc controller such as the APC or the Meanswell will supply up to (4) of the type of LED Emitters I had in mind (4 x 3.1 Vdc = 12.4 Vdc). And, the controllers are limited with respect to the amount of current they will supply, so we can drive them with a Potentiometer to maximum, but not over driver them. The Meanwell is just slightly over 1 Amp, which is the maximum for the CREE LED I had in mind, and the APC is probably even better, at 750mA maximum current, just to be on the safe side.

My contacts did advise that the emitter circuit could be embellished to operate like the strip light circuit, and that under those circumstances, the strip light controller would work fine. But, only by adding current limiters and/or resistors. But, that's impractical for me without a schematic from an experienced engineer. I don't have a clue about the values for the current limiters, and/or the resistors, or where and how to apply them in a circuit.


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## TropTrea

Yes I think you got the jest from the last post. 

On the different APC drivers available I believe your looking at a max 4 on each of the color LED's. With the APC Drivers you have a selection possibility of 12 Watts, 16 Watts, 25 Watts, and 35 Watts dependent on the number of LED's you want to run. Each series is also available at various currents 350ma, 500 ma, 700ma and 1050 ma.

For the CREE colored LED's I would run them at either 350ma which is about 1 Watt, or 500ma which is roughly 1.5 Watts or at 700ma which is roughly 2,0 Watts each.

To find uot how many can be run in a series simply take the wattage rating of the Driver and divide that by the current it will be driving. An example is if you took an APC 16-350 driver you would take the 16 Watts and divide that by 0.350 which would give you a max of 42 Volts. Then since you know each LED will draw roughly 3 Volts you can divide the 42 Volts by 3 Volts to give you 14 LED's. For saftey reasons I never run them up to the max so in this case would only run 12 or 13 LED's max. Ususally it is advisable to run at lest 1/2 the max number to meet any minimum voltage thresholds of the controller as well. 

Those little strip LED's are basicly another animal completely. But just think if the are only 0.06 Watts each 300 of them will only use 18 Watts. These have been around for years and I doubt if the technology in these is even close to as efficient as the newer CREE and Philips LED's are today. Remember they just broke the 200 lumns per watt point and only 5 years 80 lumns per watt was the best you could find in any LED's.


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## Quizcat

I was thinking the same thing you are about the wattage output only being around 18 Watts from a complete strip based the way my electrical engineering friend presented his original explanation.

So, I asked him specifically if the complete LED strip light, 300 LEDs, 16.5', which they claim produces 72 watts of light, is only producing around 18 Watts.

He gave me a little further explanation with regard to the amount of light that can expected to be generated by the LED strip light, and it's not as bad as I thought.

Here is his reply:

"Each diode uses 0.02Amps at ~3.3Vdc, but in series of 3, use 0.02Amps at 12Vdc, 0.24 Watts (with the resistor). Each segment has 3 colors, so 0.72 Watts. Times 100 segments in 5 Meters, 72 Watts, not adjusting for voltage drop in the 5 Meters. About 20% of the blue and green is wasted in the resistors as heat, more like 45% for the red, per segment. Considering all on for white, your looking at probably 60W being converted into light..."

At least from a combination of the LEDs being all on, there is sufficient wattage to deliver about 3 watts of 6400K per gallon for the plants from the strip light, which would be fine for my own purposes, since I would be utilizing the Cool White LEDs at full power most of the time, along with some color LED intensity depending on the view. I would only be activating the color LEDs at full power, and possibly dimming the Cool Whites for visual effect, on rare ocassion for my own viewing pleasure. So, the strip light has more potential than I originally thought based on my friends original explanation.

I have built strip light aquarium light fixtures before, for my grandson. But, it was only intended for viewing, since he doesn't have any live plants, and the visual effects of the strip light turned out very well. However, I want to gain some knowledge working with the emitters in a circuit, and want to work with them specifically to expand my own knowledge of how they work, etc...So, I will probably experiment with the LED Emitter light using APC controllers sometime in the near future.

I would need to deliver at least 3 watts per gallon for the plants using the CREE LED Emitters (20 gallon tank). So, based on your prior post, and your referring to making a selection from the voltage/current limitation options that are available through APC, in order to be on the safe side, which of the APC wattage/current delivery options would you choose from the APC lineup, keeping in mind that I need to acheive the 60 Watts of light that needs to be generated in the tank for the plants? Do you think I should still go with the 12 Volt/750mA option, or should I bump it up a notch? The CREE LED Emitters that I'm considering are rated at 12 Watts/1 Amp Each (4 Watts per Color). I think you may have been considering CREE LED Emitters that delivered less than 12 Watts each in your prior post. So, I just wanted to clarify that the ones I'm considering are rated at 12 Watts Each (4 Watts per color each) to make sure I'm reaching the proper technical conclusions with respect to what the Emitters will require to operate properly with respect to the controller, and still remain on the side of "safety."



TropTrea said:


> Yes I think you got the jest from the last post.
> 
> On the different APC drivers available I believe your looking at a max 4 on each of the color LED's. With the APC Drivers you have a selection possibility of 12 Watts, 16 Watts, 25 Watts, and 35 Watts dependent on the number of LED's you want to run. Each series is also available at various currents 350ma, 500 ma, 700ma and 1050 ma.
> 
> For the CREE colored LED's I would run them at either 350ma which is about 1 Watt, or 500ma which is roughly 1.5 Watts or at 700ma which is roughly 2,0 Watts each.
> 
> To find uot how many can be run in a series simply take the wattage rating of the Driver and divide that by the current it will be driving. An example is if you took an APC 16-350 driver you would take the 16 Watts and divide that by 0.350 which would give you a max of 42 Volts. Then since you know each LED will draw roughly 3 Volts you can divide the 42 Volts by 3 Volts to give you 14 LED's. For saftey reasons I never run them up to the max so in this case would only run 12 or 13 LED's max. Ususally it is advisable to run at lest 1/2 the max number to meet any minimum voltage thresholds of the controller as well.
> 
> Those little strip LED's are basicly another animal completely. But just think if the are only 0.06 Watts each 300 of them will only use 18 Watts. These have been around for years and I doubt if the technology in these is even close to as efficient as the newer CREE and Philips LED's are today. Remember they just broke the 200 lumns per watt point and only 5 years 80 lumns per watt was the best you could find in any LED's.


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## TropTrea

Quizcat said:


> I would need to deliver at least 3 watts per gallon for the plants using the CREE LED Emitters (20 gallon tank). So, based on your prior post, and your referring to making a selection from the voltage/current limitation options that are available through APC, in order to be on the safe side, which of the APC wattage/current delivery options would you choose from the APC lineup, keeping in mind that I need to acheive the 60 Watts of light that needs to be generated in the tank for the plants? Do you think I should still go with the 12 Volt/750mA option, or should I bump it up a notch? The CREE LED Emitters that I'm considering are rated at 12 Watts/1 Amp Each (4 Watts per Color). I think you may have been considering CREE LED Emitters that delivered less than 12 Watts each in your prior post. So, I just wanted to clarify that the ones I'm considering are rated at 12 Watts Each (4 Watts per color each) to make sure I'm reaching the proper technical conclusions with respect to what the Emitters will require to operate properly with respect to the controller, and still remain on the side of "safety."


First off 3 Watts of light per gallon from Cree LED's is much more light than you probably realize. If you were to light a 20 gallon thank like this you would be using 60 Watts total and on the bases of using XM-L2 -U2 LED's which are rated at 10 Watts each with 6 of them you would have

700 ma = 2 Watt per LED or a total of 12 Watts and minimium of 2,046 lumens
1000 ma =3 watts per LED or a total of 18 Watts and a minimium of 2,472 lumens
1500 ma = 5 Watts per LED or a total of 30 Watts and a minimium of 3,480 lumens
2000 ma = 7 Watts per LED or a total of 42 Watts and a minimium of 4,368 lumens
3,000 ma = 10 watts per LED or a total of 60 Watts and a minimium of about 5,000 lumens

Note running them at 2 Watt gives you about 170 Lumens per Watt but as you increase the current you loose effeciency as you also increase the light up to the max rating where your only getting 83 lumens per Watt. In terms of effeciency it has decreased by 1/2 but in total light output it more than doubled.

You have simular difference between the other groups of LED's. This is why I like to run them on either 700ma or 1050 ma drivers as then they are in an ideal efficiency range.

But you also compare these numbers with florescent lighting. A typical GE 6,500K T-12 bulb will give you 75 Lumens per Watt. So running the 6 LED at 18 Watts total is = to a 42 Watts of florescent lighting, and running them at 42 Watts total is equal to 58 Watts of florescent lighting.

If you wanted to get up to the level of 60 Watts of florescent lighting I would run 12 LED's @ 700ma for a total of 24 Watts. From personal experience though I would not go even go that bright.


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## Quizcat

I'll present it as I understand it, with one caveat with respect to comparing lumens and florescent lamps versus LEDs, in order to arrive at the proper amount of usable light that needs to be delivered to plants.

Oh, and you're right, I stand corrected, the CREE XM-L is only 10 Watts per LED, not the 12 Watts I may have mentioned before.

If I have just the Cool White part of the LED (6400K) on at full power, then it would seem that I would only be delivering around 2.5 watts of cool white light at 6400K, driven at 1 Amp (with some minor line losses). Plus, there would be some additiional beneficial light from the other colors, if they're on, and depending on their intesity, all be it at a really reduced useable output when fully activating the reds and blues (45% of 2.5 watts from the reds and 20% of the 2.5 watts from the blues).

With all colors on, the maximum usable wattage that just one CREE XM-L is capable of delivering is really closer to about 5.7 watts/LED (all colors on at their full power @ 1 Amp, not considering line losses). If I reduce the number of amps being delivered, below the maximum per LED of 1 Amp, then that would further reduce the wattage of light being delivered per LED. But, assuming a 1 Amp driver, then I would need around (10) LEDs to get close to 60 watts, and probably (11) LEDs if I drive the circuit at 750mA.

Red @ 45% = 1.37 watts per LED
Blue @ 20% = 2 Watts per LED
Cool White @ 2.5 Watts = 2.5 Watts per LED
Total = 5.7 Watts per LED
5.7 Watts/LED x 10 = 57 Watts
5.7 Watts/LED x 11 = 62.7 Watts

Takiing these assumptions one step further, if I wanted to have sufficient light for plants that use high levels of light, then I would need (17) LEDS ](*,)] in order to deliver 5 Watts/Gallon in a 20 Gallon Tank 

I'm focused on the 60 watts because of the watts/gallon theory, since the measurement of lumens, according to everything I've read, isn't an accurate measurement of usable light energy for plants, but only a measurement of viewable light perceived by the human eye. And, of course, neither is watts per gallon an accurate measurement of usable light, so they say. But, watts per gallon is the poor man's traditional way of measuring what should be delivered to the plants short of measuring "PUR."

I assume you can correlate how the LEDs perform with respect to lumens based on your experience with what the T12s are putting out, and make assumptions with respect to how to design an LED fixture to perform using the T12 performance as a standard. In that case, perhaps the amount of light being delivered in lumens in a particular tank from a T12, where the plants are doing well, can be correlating by tank size, plant type, substrate, etc...But, I have never heard of the application of lumens used in the same way as watts per gallon in light fixture design for the aquarium. I have read that lumens are only relevent to what is perceived by humans, and not applicable to what can be used by the plants with respect to intensity.



TropTrea said:


> First off 3 Watts of light per gallon from Cree LED's is much more light than you probably realize. If you were to light a 20 gallon tank like this you would be using 60 Watts total and on the bases of using XM-L2 -U2 LED's which are rated at 10 Watts each with 6 of them you would have
> 
> 700 ma = 2 Watt per LED or a total of 12 Watts and minimium of 2,046 lumens
> 1000 ma =3 watts per LED or a total of 18 Watts and a minimium of 2,472 lumens
> 1500 ma = 5 Watts per LED or a total of 30 Watts and a minimium of 3,480 lumens
> 2000 ma = 7 Watts per LED or a total of 42 Watts and a minimium of 4,368 lumens
> 3,000 ma = 10 watts per LED or a total of 60 Watts and a minimium of about 5,000 lumens
> 
> Note running them at 2 Watt gives you about 170 Lumens per Watt but as you increase the current you loose effeciency as you also increase the light up to the max rating where your only getting 83 lumens per Watt. In terms of effeciency it has decreased by 1/2 but in total light output it more than doubled.
> 
> You have simular difference between the other groups of LED's. This is why I like to run them on either 700ma or 1050 ma drivers as then they are in an ideal efficiency range.


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## TropTrea

There realy is no 100% correct and accurate correlation between LEd and Florescent lighting. Yes the old theory for florescent lighting was in the range of 3 to 5 watts per gallon which was established years ago when florescent tubes were delivering in the range of 60 lumens per gallon, and had a majority of there spectrum in the green range. Then people started measuring PAR which was closer to what plants actualy can use however PAR also rates green light the same as Red and Blue but unlike lumens it is weighted in favor of green light.

With LED's that are properly selected you actually need less lumen or even PAR than you need with florescent light. You can concentrate more light in the red and blue photosynthetic part of the spectrum with LED's which is what the plants need and reduce the amount of green light which is only there for your viewing pleasure. 

With LED's it can be a balancing act between what the plants need and what is pleasing to your eye. The most effecient photosynthetic LED lighting for photosynthesis would include only blue and red LEDs. The Lumens rating would be very low but the PAR rating would be probably about 1/2 to 2/3 of what you would get equivalent florescent lighting that was just as good for the plants. The draw back though would be your tank would look very purple and most people would hate that. So green light is added in just enough quantity to please the beholders eye. But everyone's eye is slightly different and some want more green light than others. 

Now for getting calculations on your 5 Watts per gallon lets start with a base you 17 LED's and assume they were all XM-L2 -U2. Your aiming at the equivelent of 100 watts of florescent lighting so you want 7,500 lumens. On the 17 LED's that would mean you need 440 Lumens per LED. This is close to what your get running 17 of them each at 1000ma or three watts each for a total of 51 watts. Half of what you would use with florescent lighting.

Now rather than running all XM-L2 -U2 we pull some of these LED's and replace them with red and blue LED's. While these LED's are more effecient in terms of light energy per watt they fall short on the lumens scale because lumens does weight red and blue light like they rate green light. If we put in 3 Blue LED's in replacement of white leads we cirtualy double the total output of blue light hil reducing the red and green light by only about 17%. Similarly if we replace 3 more whites with reds we double the red light while reducing the blue and green light by 17%. Overall we reduced the lumens meter reading less the 70% of what we originally had but the photosynthetic light to the plants has doubled. 

So using a vase of your 17 LED's to give the same light to plants as 100 Watts of florescent by using this combination we are giving the plants the equivalent of 200 Watts of florescent lighting and can reduce our total LED count to 9 LED's to match the amount of florescent light which the plants can utilize. Your total Wattage used now drops to 27 Watts total with roughly 2 blue, 2 red and 5 white LED's.


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## Quizcat

Great Explanation! I am learning a lot! I had no idea that the LEDs were that much different than the florescents with respect to wattage and lumens delivered.

So, if I am understanding correctly, I should go with the (5) XM-L LEDs, then add (2) 3-Watt(?) Reds, and (2) 3-Watt(?) Blues, between the XM-Ls? I should have enough room to do that...Then, any green that I might want to temporarily add for visual effect, when I just want to stand back and admire, would probably be sufficient drawn from within the XM-Ls.

So, I would need (6) single channel controllers, (4) controllers for the XM-Ls, to control each color on the XM-Ls, and one each for the 3-watt Reds and 3-watt Blues in series. I'll have to check and see if they have multiple channel controllers. It might help to reduce the footprint of the number of controllers needed if I can find them with multiple channels.

Do you recommend the Red and Blue LEDs be (3) Watts, or more, or less?



TropTrea said:


> So using a vase of your 17 LED's to give the same light to plants as 100 Watts of florescent by using this combination we are giving the plants the equivalent of 200 Watts of florescent lighting and can reduce our total LED count to 9 LED's to match the amount of florescent light which the plants can utilize. Your total Wattage used now drops to 27 Watts total with roughly 2 blue, 2 red and 5 white LED's.


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## TropTrea

Quizcat said:


> Great Explanation! I am learning a lot! I had no idea that the LEDs were that much different than the florescents with respect to wattage and lumens delivered.
> 
> So, if I am understanding correctly, I should go with the (5) XM-L LEDs, then add (2) 3-Watt(?) Reds, and (2) 3-Watt(?) Blues, between the XM-Ls? I should have enough room to do that...Then, any green that I might want to temporarily add for visual effect, when I just want to stand back and admire, would probably be sufficient drawn from within the XM-Ls.
> 
> So, I would need (6) single channel controllers, (4) controllers for the XM-Ls, to control each color on the XM-Ls, and one each for the 3-watt Reds and 3-watt Blues in series. I'll have to check and see if they have multiple channel controllers. It might help to reduce the footprint of the number of controllers needed if I can find them with multiple channels.


Why use 4 sperate controlers for the 4 XM-L LED's? You can very easily use one APC Controler to control all 4 of them if they are wired in series.



Quizcat said:


> Do you recommend the Red and Blue LEDs be (3) Watts, or more, or less?


The colored LED's are capable of handling the 10 Watts that XM-L LED's can handle. They are basicly XP-E LED's. The Reds in particular @630 nm have max current rating of 700ma at which point they will use about 2.75 Volts resulting in them being a max of about 2 Watts. The blues have a max of 1000ma at which point they will use about 3.5 Volts giving them a max of 3.5 Watts. If you run them both at 700 ma the blues will draw about 3.25 Volts and run at about 2.27 Watts each fairly balanced to the red LED's.

You could even get away with one Driver of 700 ma to drive both the red and blues and with three of each you would be drawing 18 Volts. The APC 25-700 would work great for this or you can go with two APC-12-700 one for red and one for blue. Cost is very similar.

For the 4 XM-L's I would run them on a 1050ma driver like the APC-25-1050. And you would have more than enough light in total.

If you wanted to get rid of the blues and red for viewing you would simply turn off the red-blue drivers. With just the whites it would more than bright enough for viewing.


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## Quizcat

Maybe were are getting the two kinds of LEDs confused...Or, perhaps, I am confused as to how the XM-L RGBWs can be controlled. From the comments in your previous post, it sounds like the individual "colors" within the XM-L RGBW LED don't need to be independently controlled, meaning all colors functioning simultaneously together depending on the amount of current you apply using an adjustment on the controller. Is that correct?

The other option that I had also talked about in my initial post, and perhaps this is what you were aluding to in your prior post, and what has confused the conversation, is that I am expecting to receive (5) Cool White 10 Watt (6500K) LEDs from China, the off branded ones. I could wire them up in series, run back to one controller, then supplement with REDs and BLUEs between the Cool White LEDs. But, the voltage that they run at is 9-12Vdc, so powering them may be a more difficult challenge using the controllers we are discussing. That's why I began to consider the CREE brand LEDs, which are 3.2Vdc each, and would work well with the controllers.

As you can see, the lumen output on the "COOL WHITE ONLY" LEDs below is pretty high, and with (4) of them in series, they would be really, really bright! But, also, I think that working with them would be more difficult than with the CREE XM-L RGBW LEDs because the CREEs are already on PCB heat sinks. I am not sure about the "Cool White Only" ones below. I may need to mount them some way, add heat sinks, etc...to deal with the heat factor.








Here are the specs on the Cool Whites coming in from China

Wattage: 10 Watts
Input Voltage: DC9-12V
Forward Current: 900MA 
Chip: Genesis's 30Mil 
Lumen: 900LM	
Size: 20mm	
Beam Angle: 140 degrees
Life Span: 50,000 hours

With regard to my using the XM-L RGBWs instead of the COOL WHITEs from China, please check out my next post. I have diagrammed what I had in mind using the (6) controllers, and using the CREE XM-L RGBW LEDs, supplementing with some Reds and Blues (XP-Es) between the CREEs.



TropTrea said:


> Why use 4 sperate controlers for the 4 XM-L LED's? You can very easily use one APC Controler to control all 4 of them if they are wired in series.


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## Quizcat

Conceptually, I was thinking of using (6) controllers, (4) for the XM-L RGBW LED circuit, and (2) for the Supplemental Red and Blue 3-Watt Circuits. But, I could be way off base on this.

Here is the layout of what I had in mind with respect to individually controlling the colors within the LEDs. You'll have to click on the images to blow them up big enough to actually see what I had in mind.








XM-L RGBW LEDs

What I'm unsure of is whether it's actually even desireable to independently control the colors in the XM-L RGBW LEDs. Perhaps varying the intensity of the colors together, through only one controller is just as well. If independent control of the colors is unecessary, then all the colors could each be connected in series, and run off of one controller, whereby the intensity of the colors would not have independent control, but would be simultaneously controlled off of one controller. I was just thinking that it might be nice to have independent control of the colors, especially because the Cool White portion of the XM-L RGBW LED has 6400K already, and the Reds, Blues, and Greens could be inpendently controlled for visual effect, or the REDS and BLUEs controlled independently to enhance plant growth, etc...But, maybe that's overkill, and I would be just as well off using one controller. It certainly would be a little cheaper using a single controller.








3-Watt RED and BLUE

Then, what I was also considering was supplementing the (4) XM-L RGBW LEDs by inserting (2) each of the Red and (2) each of the Blue LEDs situated between the XM-L RGBW LEDs, each color on it's own series circuit, each combination of RED and BLUE with wiring running back to their own controllers in much the same manner. Except, if I wire 3-Watt LEDs back to their own controllers, one series circuit for RED and one series circuit for BLUE, then I would probably need at least four each of them in series, since they run off of 12Vdc because the LEDs are around 3.2Vdc each. Conversely, I could control the supplemental REDs and BLUEs, all together connected in series, and run them off of one controller, and not vary the intensities of the REDs and BLUEs independently. But, here again, maybe the addition of the 3-Watt Reds and Blues, if I have independent control of the inidividual colors in the XM-L RGBWs, is over kill.

I am just a novice at this, and just trying to learn so I don't blow everything out in the process of learning. Thanks very much for your help!


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## TropTrea

First off the XM-L RGBW LED's is what is putting me off and confusing me from what I'm used to be doing. What you really have here is 4 emitters mounted on one mount. On that single mount you probably have
one XM-L Cool White LED that is normally rated at 10 Watts max.
one XP-E -G2 Green LED that is normally rated at 3 Watts max
one XP-E -B3 Blue LED that is normaly rated at 3 Watts max
one XP=E- R2 or (2 LED that is normaly rated at 3 Watts Max.

Because the LED's are located so close together cooling becomes an issue so they do not rate the combination at 19 Watts but only at 3 Watts maximum. Personaly I would not even run them that high unless you want to invest in cooling as well. With the combination you could run the Whites with a 1050ma driver giving about 3 Watts of power to each of them and then reds and blues on a 700ma driver giving them about 2 Watts each. If you really want to run the green LED's then I would even switch to a 350 ma driver for the Red, Blue and Greens running them at 1 Watt each.

If you are going to be 4 of the Combination chips with three channels and you want additional reds and blues as added idea is to just get XP-E RED (650nm) and Royal Blue (455nm) chips. These are the same chips as you have in the multichip mounts so you run the 7 Chips together on one controller for red and another for blue. This would give you a max of 21 Watts of light on either red or blue as well give you the ability to tune the red verses the blue to your personal eye taste. 

The use of two ELN 30-48 would allow you to adjust the lighting level of the blue and red LED's between 0 and about 15 Watts as you felt fit. Then for your Whites You can use an APC 25-1050 Driver so you can run them at 3 Watts each for a total of 12 Watts. If you wanted more White Light you could add three single LED's mounted XM-L Neutral White LED's to the mix and wire them in the same series with the mufti white LED's running them for a total of 21 watts of White light.


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## Quizcat

Yes, that's what I thought, that we might have been confusing one type of LED with the XM-L RGBW LED. So, I wanted to clarify that we are possibly talking two different kinds of setups so there wouldn't be any misunderstanding. 


TropTrea said:


> First off the XM-L RGBW LED's is what is putting me off and confusing me from what I'm used to be doing....


Question, so the COOL WHITE Side of the XM-L RGBW LED will generate 10 Watts, but the rest of the colors only generate 3 Watts? That is how they divide up? Because, I was under the impression that it was an equal division, 2.5 Watts for each, making a total of 10 Watts if all are on full power. That was just my impression, but I have nothing to really base that on, other than equallly dividing between what the overall LED is rated at. Apparently, the wattage output varies between the colors? This is where the allocation of wattage, and delivery of useable light begins to confuse to me. 


TropTrea said:


> What you really have here is 4 emitters mounted on one mount. On that single mount you probably have
> one XM-L Cool White LED that is normally rated at 10 Watts max.
> one XP-E -G2 Green LED that is normally rated at 3 Watts max
> one XP-E -B3 Blue LED that is normaly rated at 3 Watts max
> one XP=E- R2 or (2 LED that is normaly rated at 3 Watts Max.


Yes, that was developing into another one of my concerns as well, too much heat! But, not having had experience with these types of LEDs, that was going to be one of my next questions for you with regard to my using the XM-L RGBW LEDs, which you already anticipated. I would rather not have to get into dealing with cooling fans if possible.


TropTrea said:


> Because the LED's are located so close together cooling becomes an issue so they do not rate the combination at 19 Watts but only at 3 Watts maximum. Personaly I would not even run them that high unless you want to invest in cooling as well...


I agree with your idea of the 350mA driver for the green part of the LED, perhaps even for the reds and blues as well as the greens. I am growing more and more concerned about the heat that might be generated if I drive them all too much. But, then I come back to wanting to deliver a certain amount of wattage to the plants. If I step down on the drivers too much, then it'll have an effect on the watts/gallon. 


TropTrea said:


> With the combination you could run the Whites with a 1050ma driver giving about 3 Watts of power to each of them and then reds and blues on a 700ma driver giving them about 2 Watts each. If you really want to run the green LED's then I would even switch to a 350 ma driver for the Red, Blue and Greens running them at 1 Watt each.


Yes, I really like having the ability to vary the intensity of the individual colors within the LEDs, mostly just for viewing pleasure because I can accomplish my main goal of nourishing the plants with just a straight series circuit of several COOL WHITE (6400K) LEDs.


TropTrea said:


> If you are going to be 4 of the Combination chips with three channels and you want additional reds and blues as added idea is to just get XP-E RED (650nm) and Royal Blue (455nm) chips. These are the same chips as you have in the multichip mounts so you run the 7 Chips together on one controller for red and another for blue. This would give you a max of 21 Watts of light on either red or blue as well give you the ability to tune the red verses the blue to your personal eye taste.


I think this might be a suggestion that has very interesting possiblities...Is there too much of a heat factor on this one if I drive them as suggested?


TropTrea said:


> The use of two ELN 30-48 would allow you to adjust the lighting level of the blue and red LED's between 0 and about 15 Watts as you felt fit. Then for your Whites You can use an APC 25-1050 Driver so you can run them at 3 Watts each for a total of 12 Watts. If you wanted more White Light you could add three single LED's mounted XM-L Neutral White LED's to the mix and wire them in the same series with the mufti white LED's running them for a total of 21 watts of White light.


I know we have enough here to write a book, and I didn't mean to get so wordy in some of my explanations and conceptual details. But, it is very confusing and convoluted when you consider all the possibilities. I sincerely do appreciate your advice and experience. I'll consider my alternatives and go from there. But, I wanted to thank you very much for sticking with me on it. It helps immensely to run it by somebody that has some experience, even though it may not be what you're used to dealing with. It still helps a lot! So, thank you very much! Were you able to review my sketches of the series circuits? Based on those concepts, did you see any glaring errors that might result in my having problems with the way I anticipate wiring up the series circuits? Does it seem like I am getting it with respect to the way they're supposed to be wired up?


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## TropTrea

Do not concern yourself about Voltage. The current is what determins if a LEd will glow with 1 Watt of power or with 10 Watts of power. Do to variances in batch numbers if you think vlotage is what controls brightness you wil just end up roasting LED's. Some LED's will consume 2.75 volts at 1 watt and 3.25 volts at 10 watts so a slight line fluctuation in voltage can cause drastic changes. The LED's in your mulltiChip will deliver very similar Wattages at the same currents. The 10 Watt white LED can handle up to 3,000ma while the others can just handle 1000ma. But as I aid if you run them all at max you would have heating issues.

As far as heating issues go I run by a rule of thumb that for every Watt of light you have 4 square inches of cooling surface . So with a simple rail made from a 1" X 2" aluminum channel 8" of cooling area for each inch of length. With a 30 inch piece you will have 240 square inches of cooling surface which means you can run 60 Watts of LED's on that run without adding fans. If you add fans that boosts you by an extra 25% so you could run 75 Watts on that rail. They will be warm to the touch but not above the temps that would effect there operation. With only about 40 watts your more than safe. 

I personaly like to keep a 4" spread between LED's for saftey sake. On a 30" rail it would allow you 7 per rail so I would go with 2 Rails in your case. Then they do not even feel warm


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## Quizcat

I received the (5) 10-WATT "COOL WHITE ONLY" (6400K) LEDs from China yesterday...I think these cost me about $3.56, including shipping from China, and not each, but for all five. They are extremely economical! I don't know their quality, but they claim an anticipated life of 50,000 hours in their advertising.









They came in the little cute gift box above...  Very thoughtful and quaint, yes?









Anyway, I tested them all individually using a 12Vdc power supply that was powered from a .450 Amp transformer, and they each work perfectly individually. I never tested them in series.

They are REALLY, REALLY, REALLY BRIGHT, visually!!!! I could not even attempt looking at them without damaging my eyes, and I only had one of them hooked up to the power supply at a time.

The specs on the individual LEDs say 12Vdc @ 900mA each @ 900 Lumens each. I was only driving one of them at a time to test each one, with less than a .450 Amp transformer, and they would have damaged your eyes if you tried to look directly at them. I had to look away, off to the side, etc...or they would leave a black spot in your field of vision, which cleared up pretty rapidly, but they are not something that you can safely look directly at. I don't know how the visual brightness translates into usable light with respect to the plants, but visually they produce an unbearable amount of visual light!

So, I want to make sure that I understand how these should be powered, and what kind of performance to expect. Based on my seeing their brightness visually, I would assume that you wouldn't need more than two or three of these in a light fixture to get a very significant amount of cool white light being generated in a 20 Gallon Tank.

They have a 140 degree Beam Angle. So, I think I could probably get by with two of these with respect to illumination in the tank, maybe three of them if I wanted a maximum amount of light without causing a color temperature issue.

Please tell me if the following assumptions are correct...

If I want to have two of them in series, since they are 10 Watts each, two of them in series are capable of putting out close to the about 40 watts of florescent light, and three of them are capable of putting out about 60 watts of florescent light? Is that correct?

Since they are rated at 900 Lumens each, two of them in series would generate about 1800 Lumens in the tank, and three would likely generate 2700 Lumens, all at full power of course.

If I want to drive two of them, I would need a controller that has at least up to 24 Vdc available, because there are two of them in series at 12Vdc each? And, if I wanted three of them in series, I would need at least 36Vdc to power them? Am I understanding correctly that in selecting a driver to drive them, the voltage that the driver needs to be capable of putting out should be whatever the rated voltage for each one is, times the number of LEDs in the series circuit. Is that correct?

They have a maximum amp rating of 900mA each. So, even if I have two or three of them on series, as long as I stay under 900mA on the driver output (around 750 Amps), I should be ok, right? And, if I wanted to vary the brightness of them in series, I assume that I could get a dimmable driver, so I can vary the amps up to 900 Amps. Is that right?


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## TropTrea

What your picturing is a combination chip with 9 emitters individually wired in a series parrelell circuit so that you can apply up to 12 volts and 900 ma to them max. These are low cost emitters (1990's designed emitters) that are rated individually at probably 3 Volts and 300ma each. Yes in a tight combination like this they produce a lot of light. I would run all five of them with a single APC-35-500 driver. The combination should give you roughly 2,100 lumens.

Now these are 6,400K LED's which should be rich in the blue light spectrum but not produce much red light. Therefore I would supplement them with 6 X-PE Red LED's preferably P2's that peak at 655nm but if you cannot get them then go with R2's that peal around 620nm. I would run these on a APC 12-700ma driver which would give you roughly an added 6.5 Watts or about 400 more lumens. 

You have a total of about 36 Watts of power so for cooling you need about 146 square inches of cooling surface. With 1" X 2" channel aluminum that means you need a section at least 19" long so you should be safe running a single rail the length of a 20 gallon tank since it is between 24" and 30" long.

A bit more light than I would put on this tank but dependent on the quality of the LED's you should me in the medium to very high light range which I believe you originally wanted.

The old combination Chips you had I'd put on the side for a future project.


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## Quizcat

The COOL WHITE LEDs are supposed to be 10 Watts each, and they are advertised to produce 900 Lumens from each LED. So, when you say that they should produce about 35 Watts total, instead of 50 Watts, and only 2100 Lumens total, instead of 4500 Lumens for all five in series, I am curious as to why, and if you have a formula in mind that you use to calculate the results you got. And, is that figure of 36 Watts including the (6) Reds?

I may be answering my own question with what follows. I hope I am starting to finally pick up on what you've been recommending all along, but please humor me if I am sounding slow in catching on, and overly redundant...](*,)

I was initially thinking that all five of the COOL WHITEs would produce around 50 Watts of light, and about 4500 Lumens from all five. That's why I originally thought that three of them would be sufficient.

Is it because you are only intending to drive them at 500mA instead of 900mA that you are getting a total wattage of only 36 Watts? That does seem to be your advice in prior posts, to drive them at a lower threashold to reduce the heat factor, and for safety's sake.

I ask because I would not have thought about that without you pointing it out again. I would have guessed at my needing a controller that needed to put out at least 45-50 Watts, and probably selected a controller that would have delivered maybe 700mA if I used all five of them in series.

It seems that by reducing the current output, and you are recommending nearly half of the maximum current of 900mA, that I can reduce the amount of wattage that I anticipate needing when selecting a controller. Is that right? That's why I'm asking if you're using a formula of some kind to know what wattage and current to recommend.



TropTrea said:


> I would run all five of them with a single APC-35-500 driver. The combination should give you roughly 2,100 lumens.


And, along that same path, do you have a particular formula that you use to calculate the kind of cooling effects needed when you recommend a certain width and length of channel aluminum? I wonder if I can get that at Lowes or Home Depot? I have access to those heat sinks that I posted the photo of in one of my prior posts. But, I imagine it might be less expensive, and possibly even more efficient, to go with the aluminum channel. Plus, they would probably only sell it in 8' lengths, and it would be even more economical because I could use it in other light fixtures, assuming I build more than one. And, I do have space in the fixture housing for two of them side by side for even better cooling effects if I have to buy it in a longer piece. 


TropTrea said:


> With 1" X 2" channel aluminum that means you need a section at least 19" long so you should be safe running a single rail the length of a 20 gallon tank since it is between 24" and 30" long.


Yeah, I agree for now. I want to master the light that uses the 1990's COOL WHITEs first until I gain a little more experience. Plus, the footprint for the controllers that would be necessary to drive the multiple LED Emitters isn't really something I want to deal with right now. Except...I am wondering if using the multiple color emitters, the XM-L RGBWs, might not be a wiser purchase now instead of the solitary Reds, just because I may want to drive all four of the colors later on, and it would be easy to hook them up to individual controllers if I already had the XM-L RGBWs, instead of having to buy them, and replace the REDs in the fixture. Because, I think I could hook up a controller to the RED side only on the XM-L RGBWs, and still drive them with the same controller you suggested, correct? But, maybe the color temperature (K Rating) that would be generated by the XM-L RGBW (Red Cell Only) isn't quite as good as what would result if I were able to deliver supplemental RED light to the tank from the XP-E P2s. I checked briefly for the XP-E P2s and haven't been able to locate any so far via Ebay. The others you recommended are available, but they do have a lower "K" rating than the P2s. I'll have to check how many Kelvins the Red cell of the XM-L RGBWs puts out to know if they would be an acceptable alternative to the P2s, but I kind of doubt they'll be any better than the R2s.


TropTrea said:


> The old combination Chips you had I'd put on the side for a future project.


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## TropTrea

First of all you were correct in the factor that I degraded the light output of your LED's by running them at 900 watts rather than 500 watts. Why did I do this?
1. I have heard from people that have used these LED's in the past. They all complained that they ran extremely hot when they were run at full power. Some of these people had extensive cooling systems. 
2. All LED's are more efficient at lower currents. They have a basic threshold current that turns them on but when you double the current beyond that you only get about 70% increase in light while using twice the electricity. 
3. For only a 20 gallon tank you do not need anywhere near 50 watts of LED lighting even if they are not the most efficient ones. Right now I have some 10 gallon planted tanks running only 2.5 watts of LED's. Sure there not high light demanding plants mainly Water Sprite, and Hornworth but I'm thinning these plants out on a weekly bases.

An old guide for free air cooling of LED's I got years ago from a distributor was 1 square inch of cooling surface per 1/4 watt of LED lighting. I tried this on one of my first fixtures and thought it was extremely too hot after 6 hours of operation. Using the 1" X 2" alumnium channeling I went to a 4 inch spacing between the LED's on my next build. With the surface area of the aluminum channeling it has an area of about 8 square inches for inch of lenght. Since I space mu LED's 4" apart that gives them roughly 32 square inches per LED. I started this when I was running the LED's at 700ma and have continued using that spacing on up to running them at even 1,400ma. At 1,400ma they are roughly using 4.6 watts so I'm giving them just under 7 square inches of surface area per watt. The rails still only get warm to the touch probably about 10 to 15 degrees over room temp.

The biggest killer of LED's is heat. Sure they are rated to run at up to 85 degrees C but they produce more light and will last longer when running closer to 25 C. Different brand names have different specs on this but I prefer staying on the safe side. If your tank and room is at 25C there is no getting away from the fact that your LED's will be running hotter than this. But the more cooling area you give them the closer they will remain to the 25C range. 

I calculated your rough total at 36 Watts. So taking two 24" channels would give you 384 square inches of cooling space. With 36 Watts of power you would have 10.5 square inches of cooling per watt. If you use a 30" channel you will have 240 square inches of cooling space or 6.6 square inches per watt. Both should be in the safe range for you.


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## Quizcat

Thank you very much! I'll be able to apply your methodology to this design using the COOL WHITE LEDs, and any future designs I might come up with...

Been dealing with a sick German Ram Ciclid the last 24 hours. I hear they're kind of tricky to keep thriving. I set up a separate hospital tank, no plants, no substrate, just a piece of blue woven filter media in the filter, and I'm treating with Tetra Lifeguard tablets.

I'm using a spare light fixture, a Marineland LED light, which came with my 29 gallon tank, for lighting. I have since replaced the Marineland light with a Current Marine LED fixture, which seems more than adequate for the Anubias and Java Fern that I have in the 29 Gallon Tank. The Marineland light has (6) white LEDs and (3) Blue LEDs, but it's not intended for growing plants, just for basic lighting needs.

I think the German Ram may have a bacterial infection of some kind. He keeps his tail all compressed, and he keeps his top fins compressed. I noticed a white spot or two, but it doesn't look like ICH to me. So, my next best guess is Bacterial Infection.









I started treating with the Lifeguard tablets this morning around 10am, and the little white spot that is on the back fin in the photos is gone. So, I am hoping it's working. The Ciclid was also staying close to the top surface of the water, which is uncharacteristic of their behavior, which caused me to notice that something was wrong. He has since moved to the rest just above the bottom now. So, hopefully he's improving. I have treat for (5) days. Then, if he looks like he's recovering, I'll move him back into the planted tank.

The other fish in the planted tank don't show any signs whatsoever of having any kinds of problems. So, I'm hoping that whatever it is, I have isolated it in the hospital tank.

My only concern is that the hospital tank doesn't have a biofilter established. I just set it up today. But, I did treat the water with Seachem Stability before acclimating him to the new tank. The Tetra Lifeguard is supposed to KILL any and all bacteria, including a biofilter, so I guess it doesn't matter. But, Ciclids like a well established tank, pristine water, etc...so, not sure if the cure is worse than the disease where a German Ram is concerned.



TropTrea said:


> First of all you were correct in the factor that I degraded the light output of your LED's by running them at 900 watts rather than 500 watts. Why did I do this?
> 1. I have heard from people that have used these LED's in the past. They all complained that they ran extremely hot when they were run at full power. Some of these people had extensive cooling systems.
> 2. All LED's are more efficient at lower currents. They have a basic threshold current that turns them on but when you double the current beyond that you only get about 70% increase in light while using twice the electricity.
> 3. For only a 20 gallon tank you do not need anywhere near 50 watts of LED lighting even if they are not the most efficient ones. Right now I have some 10 gallon planted tanks running only 2.5 watts of LED's. Sure there not high light demanding plants mainly Water Sprite, and Hornworth but I'm thinning these plants out on a weekly bases.
> 
> An old guide for free air cooling of LED's I got years ago from a distributor was 1 square inch of cooling surface per 1/4 watt of LED lighting. I tried this on one of my first fixtures and thought it was extremely too hot after 6 hours of operation. Using the 1" X 2" alumnium channeling I went to a 4 inch spacing between the LED's on my next build. With the surface area of the aluminum channeling it has an area of about 8 square inches for inch of lenght. Since I space mu LED's 4" apart that gives them roughly 32 square inches per LED. I started this when I was running the LED's at 700ma and have continued using that spacing on up to running them at even 1,400ma. At 1,400ma they are roughly using 4.6 watts so I'm giving them just under 7 square inches of surface area per watt. The rails still only get warm to the touch probably about 10 to 15 degrees over room temp.
> 
> The biggest killer of LED's is heat. Sure they are rated to run at up to 85 degrees C but they produce more light and will last longer when running closer to 25 C. Different brand names have different specs on this but I prefer staying on the safe side. If your tank and room is at 25C there is no getting away from the fact that your LED's will be running hotter than this. But the more cooling area you give them the closer they will remain to the 25C range.
> 
> I calculated your rough total at 36 Watts. So taking two 24" channels would give you 384 square inches of cooling space. With 36 Watts of power you would have 10.5 square inches of cooling per watt. If you use a 30" channel you will have 240 square inches of cooling space or 6.6 square inches per watt. Both should be in the safe range for you.


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