# lighting question



## Bluefin (Oct 29, 2014)

hello. i have a 125 gallon tank . the depth is 20 inches (after subtracting 3 inches of substrate) and it is being lighted by 4 x 36inch current sat plus pro . 
the lights sit in a canopy about 4 inches from the top of the water so in all its at a 24 inch height give or take.
what category light would you say i am in ? 

med
med/high
high

thanks for your input


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## Newt (Apr 1, 2004)

What type of bulbs are being used in the fixture?

i.e. T5, T5HO, CF biax, etc.


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## Bluefin (Oct 29, 2014)

Newt said:


> What type of bulbs are being used in the fixture?
> 
> i.e. T5, T5HO, CF biax, etc.


they are led

http://current-usa.com/aquarium-led-lights/satellite-led-fixtures/satellite-led-pro/


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## Newt (Apr 1, 2004)

There isn't a lot of information out on LEDs yet. I mean real data: spectral plots, energy output in microeinsteins. The current make up of LEDs yields very tight/narrow bands of emissions. Bright doesn't mean it has usable light by plants. I'm still in the camp that believes LEDs are not there yet for the hobby.

Perhaps someone else can help.

The best indicator is how well are your plants doing and what type of plants are you able to grow.


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## Bluefin (Oct 29, 2014)

well im growing some high light plants but what concerns me is my dwarf hairgrass, been 4 months and not grown in yet anlso is being attaked by bba which says to me its growing slow, given im dosing ei and with pressurized co2 it has to be the lights im thinking


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## Newt (Apr 1, 2004)

BBA is usually a result of 2 things out of whack: Fluctuating CO2 and low nitrate, high iron. Try keeping your CO2 steady at 30ppm (min), lower your iron dosing and raise the nitrogen levels to approx 20ppm. Also, increase flow all areas of the tank.

I've grown dwarf hairgrass in a 10 gal tank with a single 36watt CF bulb and no CO2 (just excel). They did OK. Lighting usually isn't a cause of BBA.

I don't believe in EI. It does not work for everyone.

Is your water hard or soft?


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## Bluefin (Oct 29, 2014)

soft, im in nyc


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## Newt (Apr 1, 2004)

I'm in MA. My water is super soft: KH is less than 1 deg and GH is about 1 deg. I add GH booster to bring GH to approx 5 or 6 deg and alkaline booster to bring KH to approx 3 or 4 deg. Not saying this will help with BBA but will help the plants grow better.


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## JeffyFunk (Apr 6, 2006)

Newt said:


> The current make up of LEDs yields very tight/narrow bands of emissions. Bright doesn't mean it has usable light by plants. I'm still in the camp that believes LEDs are not there yet for the hobby.
> 
> Perhaps someone else can help.
> 
> The best indicator is how well are your plants doing and what type of plants are you able to grow.


This is only partially true. The single color LEDs do have very narrow wavelength emissions but the the "white" LEDs are really composed of the blue LEDs coated with a material that causes some of the light from the LEDs to emit at lower energy wavelengths, giving you the effect of seeing all the wavelengths to produce a "white" color. The perception of that color (i.e. Cool white, warm white, etc) to ur eye is dependent upon the amount of material they add in order to change the amount of blue light to the other lower energy wavelengths.

The thing I've discovered with LEDs the hard way (and it was backed up by the LED presentation at the spring AGA convention) is the fact that u can't trust ur eyes in terms of "brightness". Ur eyes are supposedly most sensitive to green light in terms of brightness. What is means is that an LED fixture that doesn't emit a lot of green light is not going to appear as bright as a fluorescent light fixture that does have a lot of green light. Both light sources may have the same PAR value, but the fluorescent fixture will appear brighter to ur eye than the LED fixture simply because the wavelenghts of light produced by the two fixtures are different. All LED fixtures are deficient of green light - that's just the current technology limitation of LED light sources.

I switched from a TEK Brand T5HO fixture to a build my LED LED light fixture and I'm now a believer in LED lights. I'm able to grow plants I was never able to before as I believe the light source is way more powerful. NEWT is correct that you should really just observe ur plants to see how they grow.

I, unfortunately, can't comment on the original question as I don't know anything about that brand of LED fixtures.


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## niko (Jan 28, 2004)

A few more words about brightness to the human eye, PAR, and what are we really after;

Look at my DIY build:
http://www.aquaticplantcentral.com/...atic-plant-club/115178-6-ft-long-diy-led.html

The jest of all of the above is that 160W of the best freshwater T5HO bulbs you can find produce a low PAR at 24" water depth - PAR 40. And 120W of LEDs (with 60 degree optics) produce PAR of 106 BUT only in a narrow area under the LED emitter. The tank looks WAY brighter with the T5s but the PAR can not be compared.

Yesterday I added a third rail to my DIY rig. Now I have 180W of LEDs:

The PAR jumped up more than I thought - 30 instead of 15. But the visual brightness of the tank is still less than that of T5HO!

Placing the T5s back on the tank and turning them on shows very well how much light spill the T5s have. The back glass of the tank is completely lit while with 3 rails of LEDs (180W total) the back glass does not get much light because of the 60 degree optics. So the T5 looks way brighter because it spills light all over and that light bounces back and forth inside the entire tank.

Another thing about the T5s is their color - Giesemann Midday produces absolutely gorgeous light. Clean white, no yellow, but not washed cool white. If you look at a room that is lit with these bulbs you will swear that is lit by the sun itself on a clear day. The light looks perfectly natural. That can not be said for a combination of Neutral White and Cool White LEDs. Their light is good looking but only until you compare it to the Giesemann Midday.

A note about using funky colored LEDs: You can get all kinds of reds, blue, purple, whatever. And you can add them to your LED fixture and feel great about the "amazing" spectrum you created. But the reality is different - you can not add too many of these funky colored LEDs. Because the light will turn a very weird color. People sprinkle a few reds and a few blues here and there on their LED fixture. What does that accomplish? Nothing. In a few spots the light will have more red or more blue in the spectrum. Without enough intensity or coverage to do anything. I will never understand why that is so difficult to understand. Take 3 grains of salt, put them on your salad. It is not going to make any difference.

In my case, what I see is that the most brightness and the most PAR is achieved with the T5 in the middle and two rails of LEDs shedding light on both sides of the T5s. The tank looks super bright and nice. I do not think most people have seen a tank looking so good. But the PAR is about 90. Which really is a high light. Anyone that thinks they really have to have PAR more than 90 has bought into the mentality of "more is better" which killed the US hobby few years ago. For me personally, I just don't like that with lots of scattered light the back glass gets all exposed. I like the tank to look as if it has no end - the back glass is in the shade. Just personal preference.

Some numbers with 160W of DIY LEDs:

The PAR readings at 100% LED intensity.
The sensor was placed 24" below the water surface.
The sensor was in the middle of the tank (back/forth middle)
The air gap between the water surface and the LEDs is 10".

180W of LEDs (all 3 rails ): PAR 140
120W of LEDs (Front and Back rails): PAR 80
120W of LEDs (Front and Middle rails): PAR 110
120W of LEDs (Middle and Back rails): PAR 70
60W of LEDs (Middle rail only): PAR 100

-->160W of T5HO with individual reflectors: PAR 40

All of that is fine and dandy. I got me a killer PAR. Isn't that grand? But will this overkill LED rig actually grow plants? I have the feeling it will and will grow them very well. For two reasons - the light is extremely strong AND plants are adaptable. They do not need any specific tight range of conditions. Anybody that actually knows something about planted tanks will tell you that the light source doesn't really matter as long as it is "strong".

The popular notions that you need this GH/N/P/CO2/Flow/Ca:Mg/Traces/Light Spectrum/Substrate/etc.. are illusions. It is all about letting the plants adapt. And they will adapt to a man-made source of light that is imperfect compared to the Sun. We should not attribute the good growth of plants to a piece of equipment that we made.

As usual - we should look at plant growth in a holistic way. Do you really believe that a piece of electronics that makes light makes a considerable difference? I don't. My exterior security lights in front of my garage produce a higher PAR (at 4 ft distance !) than my "cool" DIY LED rig made with the best LEDs emitters you can find. And they cost $9 a piece... You think they can grow plants? Yes, but who wants to use them? This is really more about us than about aquatic plants. If we let it be that way, that is.


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## Bluefin (Oct 29, 2014)

thanks newt im gonna try all that see what happens. i dont have bba on any of my stem plants cept the hairgrass and some anubais . i feel like ripping it out but its about half grown in albeit it looks like black hairgrass.


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