# Sticky  Proper Wattage for Aquariums



## John N.

Since the watts per gallon rule seems be somewhat inaccurate in today's market of Compact Fluorescent (CF) Lighting, T5HO bulbs, Metal Halides, etc. Can we devise another way to tabulate the minimal threshold of lighting for a planted aquarium with the capabilities to grow most stem, keep a foreground of _Glossostigma elatinoides_ low, and meet the demands of other light requiring plants?

Maybe it would be easier to say from experience what it takes to grow most light requiring stem plants, and then devise a general average for each type of tank. Assuming photo period is 8-10 hours, regular fertilization and CO2 supplementation. Below is what I gather.











Let's come up with a general guideline through calculation and/or observation experience. 
Please list you tank's minimal lighting threshold to meet the needs of most stem and light require plants.

- John N.


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## redstrat

I think this is an awesome idea John, it could help clear up the confusion about the WPG rule. Maybe we can eventually define medium and low lighting for the thank sizes too. 

I'll have to say that 75gallon tanks should do well with 220-260watts CF but I can't completely back that up because I dont have pressurized CO2 yet, glosso is growing horizontal though with 260watts and my current DIY Co2.


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## hoppycalif

I use 110 watts of AHS light on a 45 gallon tank. I successfully grow and get good color in Ludwigia sp. Guinea (high light plant), Hemigraphis traian (high light plant), Blyxa japonica (medium light plant) and Alternatheria reinickii (medium light plant). So, my experience suggests that the lighting needs for a 40 gallon tank are less than you listed.


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## niko

I like that idea too.

But we must include the height of the tank, not just the volume. 

Back in 1982 I had a 10 gal tank that was only 10 inches tall. With 50 watts of incandescent light, inert gravel full of mulm, and no CO2 I could grow about 15 species of plants. I believe it was the height of the tank that made that possible.

--Nikolay


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## BryceM

I second Hoppy's feelings regarding 40g tanks. I use about 180 watts of spiral compact flourescents with virtually no reflector over my 46g tank. Real CF's with actual reflectors work certainly much better. Still, I get excellent growth in R. vietnam, Blyxa. japonica, HC, and L. 'cuba'.


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## redstrat

are you looking for "most stem plants" or growing glosso horizontally as the criteria for comparison??? granted I know these are pretty similar but I think it can be interpreted different ways.


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## John N.

It's hard to separate the two, and I think growing glosso horizontally indicates that most stem plants will grow perfectly fine. But you're right, it doesn't necessarly indicate that if all stem plants grow fine then glosso will grow horizontial.

I think the criteria for minimal lighting to grow "most stem plants" is define by the lighting required to get the best coloration and growth out of your stem plants i.e. _Hottonia palustris, Ludwigia sp. 'Guinea', Blyxa japonica, 
Limnophila aromatica, Alternanthera reineckii,_ etc. If the stated wattage also grows Glossostigma elatinoides horizontally then that's an extra bonus.

Hopefully, we as we grow through this process we can define low, medium, and high light aquariums a little better, and also narrow our definition above.

-John N.


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## niko

It's a common mistake to look at a "snapshot" of a planted tank.

For example people will suggest certain concentration of fertilizers (say 5-10 ppm N and 0.25-0.5 ppm P). But these are concentrations for a well established tank. Also when the plants grow you may need to increase the N or the P, or both.

Amano's liquid fertilizing "system" is based on the tank "phases". Simply put fertilization is not the same starting with Day 1.

Same goes for lighting. And only a couple of years ago Amano started to use daily "phases" for the light too (about 4 hours of low light, 2-4 hours of very intensive light, about 4 hours of low light).

If we want a practical and useful info on lighting we must point out at least 2 more things:

1. Duration of the lighting period (photoperiod)
2. Intensity of the light

Such pointers will save many issues in the most critical phase of the tank development - the first few weeks. Mike Senske once told us that really it's better to start a tank from scratch then to battle algae once they are developed. The first few weeks are critical in all that.

Here are my views:
*Aproach 1:*
I would start a tank with only 2 to 4 hours of 100% light intensity for the first 4 to 8 weeks. Preferably around the middle of the day. Of course - never have intense light when the plants have their leaves closed. 2 hours of good light is insanely small period and it needs to be adjusted quickly if some light loving plants are suffering.

The rest of the day the tank gets only ambient light or has very low to low light (0.5 - 1 wpg for a total of about 8 - 10 hours a day). After this initial period of up to 8 weeks the tank can be lit for 11 or even 12 hours with 100% intensity of the light.

*Aproach 2:*
For the first 4 to 8 weeks have the lights on for 8 to 10 hours a day but using only 50% of the light suggested in John's list.

To me that approach is inferior to the first one but it could be an alternative. Still - plants do prefer intense light (although for a short time) than low light for a prolonged period.

Both approaches have one goal - limiting the algae in the first few weeks of the tank life. What I've seen is that sometimes the algae seem to have an abrupt "breakdown" - they seem to "give up" trying to establish themselves in that tank.

Controlled light really messes algae up . It may not preven them 100% but it keeps them "weak". After several weeks of such weakened state I've seen them completely disappear from a tank, literally in 1 day. From that point on the tank is very, very stable and beyond clean. I have 2 such tanks here at home that have undergone that kind of development and I abuse them badly (irregular maintenance). The only problem is starved plants and slow growth but never algae.

--Nikolay


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## BryceM

niko said:


> Controlled light really messes algae up . It may not preven them 100% but it keeps them "weak". After several weeks of such weakened state I've seen them completely disappear from a tank, literally in 1 day. From that point on the tank is very, very stable and beyond clean. I have 2 such tanks here at home that have undergone that kind of development and I abuse them badly (irregular maintenance). The only problem is starved plants and slow growth but never algae.
> --Nikolay


I've seen this too. This is perhaps a bit off of John's topic, and deserves its own thread, but it's almost as if some signal tells them to pack up shop and leave town. It's a very intriguing phenomenon.


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## eklikewhoa

i have 96w over my 20H and everything seems to be growing great!

i dont have hc but i do have hm that grows low to the ground and all over the foreground actually. dose seachem's line of ferts per their rec. chart and ~30ppm of co2 i plan on switching to GW ferts that i have when the seachem stuff is gone and i have switched to pressurized already.










i had the HM growing all over the front and covering the downoi but i have since cut all the HM from the downoi area to the diffuser out for another tank.

also to add i have a 2.5g with 18w coralife pc over it and it grows riccia and HM low to the ground as well and that tank has no co2 or ferts just flora base and weekly w/c's


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## John N.

Great points Niko. It is hard to take a snapshot tank and say that's how it's going to work for everyone at all points in time. Definately ideas to be considered.

Eklikewhoa, with 96 watts over your 20 H gallon tank how long is your photo period and what fixture(s) and reflectors are you using to the 96 watts? Beautiful tank by the way too! 

-John N.


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## eklikewhoa

Oops, new I forgot something.

96w 6700k quad bulb coralife fixture on coralife legs
Open top tank
Photoperiod of 8hrs

Thanks for the comment john!


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## ruki

A couple data points.

I have an "insane" light level tank using 4 of the 6 bulbs of a 48 inch Tek Light fixture over a 55 gallon tank. It's 4 watts/gallon, but with the reflector it's equivilant to more than 6 watts/gallon from lamps with lesser reflectors.

It's a new tank, in that it's not stable yet, so I can't give good figures. Also have some algae bothering some plants I picked up a store that were contaminated with it. Need to put some fish in the tank to see if they will clean it up for me.

Just some very amusing observations for now:

Java fern adapts better to this high light than Bacopa carolina, Egeria densa and Mayaca. But the Potamageton gayi really likes it that bright. (The others had a burnt look to their leaves.) I may also just not be giving them enough nutrients for all the light they are getting.

Above it, I have two 20H's side by side with a 40 watt Grow Lux and 32 watt Octatron 6500K. Does really well for the anubias/crypt propagation tank and the low-maintenance medium light tank with misc plants.

As far as coming up with an index, I'll rephrase what I read on a posting saved at the crypt:

* Get a light meter that measures in lux and put over it a photographic filter that notches out green and gets rid of all infrared. (Is there a photographer in the house?!?) This would give us a good number that multiple people could do. Put the thing inside an empty aquarium and make measurements with different lights. (Somehow enclose the thing and make measurements in one filled with water.) This would not perfect, but this would be a much better estimate than what we have now.


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## ruki

Here's where I originally saw the photographic filter over a light meter idea, it's from 1998:

Units of PAR


> For final measurements and to compare results, as George suggests, I plan to
> use a filter over a standard cell (as found in a Lux meter) that is designed
> to allow photography in a fluorescent-lighted room with daylight film. That
> pinkish/purple filter will give comparison numbers a bit more meaningful for
> plant growth, I think.
> 
> For that, lux sucks, as does lumens. PAR is actually only somewhat better.
> My filter will basically measure relative PAR with a lux meter, even with
> different lamp spectra, by de-emphasizing the green part, which most plants
> reflect away, anyway.
> 
> Wright
> 
> Wright Huntley, Fremont CA, USA, 510 612-1467


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## Nixe

Hello (my first post)!

My tank is 80 gallon, 20" tall, 10 h lighting period and 136 W T8 + reflectors.

I grow glosso fast and absolutely horizontally.

How's this correlating with the figures in the first post, I wonder.

.Nixe


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## gibmaker

*lighting*

I have a 125 gal discus tank with 440 watts of cf on top, I use diy co2 reactors and diffusers, and I have grown glossostigma in my tank very well, It just about all died from an algae bloom, that was when I first started, as far as anything else, you name it and I can grow it I am sure of this.


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## TXaviator

*Re: The Rules of Lighting for Planted Aquariums*

uhhhh the only thing i am gathering so far is "buy as many watts as you can possibly afford"

:-\

am i wrong on that?


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## Laith

*Re: The Rules of Lighting for Planted Aquariums*



TXaviator said:


> uhhhh the only thing i am gathering so far is "buy as many watts as you can possibly afford"
> 
> :-\
> 
> am i wrong on that?


I would answer yes. 

While very high lighting (ie 4wpg+) is certainly doable, IMO it requires a certain level of experience and is definitely not an absolute requirement for a successful healthy plant tank.

You can grow pretty much anything with 2.5-3.5wpg of good lighting.

My comments relate to tanks larger than say 40l (10g). For smaller tanks more wpg is required.


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## Supercoley1

I would've lowered the minimum level in the last post. I get very good and colourful growth under 1.8WPG using T5 HO lights. Maybe the WPG (that has already been said is not so much use anymore) is for T8s and that 1.8WPG = more in comparison to both PC and T8 (although PC seems to give more intense light instead of spread light)

Much better than when I had 2.5WPG of compact flourescents!!!!

In fact I would often have centre of the tank staghorn growing on the plants directly underneath the CF lights whereas now I think the better spread of light from the HOT5 seems to be better as this phenomenon has disappeared (it never appeared when I used T8s only when I used PCs!!!!)

Andy


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## Chuppy

Wow if that is the ruling... my tank is waaay too bright then.... 20gal 55w?? Mine is 107 Watts mind you  lol


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## xjia

mine 50L (55x30x30cm),2x40w, and 2x15w..... total 110w.
plants doing well with ferts and perssurised co2.


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## Chuppy

lol mine is the 20gal.long and i have 102w over it lol!


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## Questin

I have a standard 125 Gallon tank, and 220 watts is not enough to get glosso to stay down. I currently have power compacts. My CO2 is good enough, just lacking on the lighting. The glosso does product the bubbles, but it is not staying down.


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## trag

While acknowledging the fact that lumens output varies with color temperature and spectrum of specific bulbs, etc., nevertheless, here are some rules of thumb for comparing light output. Because of the aforementioned caveats, they're rough, but that's usually expected of rules of thumb.

I based my comparisons on a survey (very non-scientific) of manufacturer's specifications for bulb output in lumens. I used the numbers for bulbs rated between 3000K and 4000K. That way I'm not comparing a bulb from one manufacturer at 3500K (high lumens) to a bulb from another manufacturer at 6500K (lower lumens). I used the nominal 4' length of bulbs for the fluorescent lights. 

So what I found is that a T12 40 watt bulb is expected to output about 2900 -3200 lumens, or from 72 to 80 lumens per watt. 

A T8 32 watt bulb is expected to output about 2900 lumens or about 90 lumens per watt.

A T5 (non HO) 28 watt bulb is expected to output 2700 - 2900 lumens or from 96 to 103 lumens per watt.

A T5 HO 54 watt bulb is expected to output 5000 lumens or about 92 lumens per watt.

Compact Fluorescents should be approximately comparable to T5 HO but a bit less efficient because they're the same technology but with some disadvantages.

Whether you actually get that many lumens, only a man with a light meter knows. But these should be useful numbers for comparison purposes. In other words, the numbers may not be right, but if they're wrong, with a little luck, they're all wrong in about the same way. 

Similarly, these numbers will be too high for higher color temperatures which are further from the green/yellow light where lumens are measured, but presumably, a 6500K T5 bulb will be proportionately more efficient than a 6500K T12 bulb.

Additionally, the current crop of High Intensity LEDs put out about 80 lumens per 1.1 watt LED at .350A or about 72 lumens per watt. When run in high output mode at .7A they output 140 lumens at 2.38 watts or about 59 lumens per watt. LEDs are improving really fast right now, so these numbers may be out of date tomorrow, but remember, that you need to use LEDs for comparison which are actually shipping in usable/affordable quantity. Just because they can do something in the lab doesn't mean that you can put one over your aquarium.

For metal halide a 70 watt bulb produces about 6000 lumens initially falling to 4800 lumens fairly quickly. I'm not sure whether to use the initial or the mean, given the very short life of these bulbs, but it's between 70 and 85 lumens per watt. Maybe a lumen or two higher per watt for the higher wattage (150 - 300 watt) bulbs.

So in terms of energy efficiency, we have a rough rating of LEDs at the low end of the scale (surprise!) then T12 fluorescent and MH in about the same neighborhood, then T8 and T5 HO neck and neck, and finally T5 (non-HO) as the most efficient lighting. Notice that these numbers are close enough together and so approximate, that different fixture and bulb choices could cause the efficiencies to overlap. Again, this is a rule of thumb for comparison purposes.

HI LED: 59 - 72 L/W
T12: 72 - 80 L/W
MH: 70 - 85 L/W
T8: 90 L/W
T5 HO 92 L/W
T5: 96 - 103 L/W

But there are other ways to measure efficiency. We could measure areametric light efficiency. In other words, how much light intensity can we get in a unit area. Considering this parameter brings up several issues that should be at least mentioned, if not discussed.

First, the efficiency of the light's reflector has a substantial impact on how efficient your light really is. Fluorescent and MH lights emit in a tubular pattern and so need reflectors behind them to try to recover 50% or more of the light. LEDs may be more directional and therefore more efficient without a reflector. Also, the further from 90 degrees (perpendicular) the angle of incidence (angle between water surface and direction of travel of light) gets, the more light is reflected at the water's surface. 

So for best light intensity, the ideal is a column of light striking the water surface perfectly perpendicular to the surface. For this comparison, we'll just assume that all the light is reaching the aquarium, or that the reflectors for each type of light are equally efficient. Keep in mind that this may do LED a disservice, because the light from LEDs is emitted pointed more or less towards the water and requires much less reflection to actually get there.

So assuming that a pair of T12s need a reflector 7.5" wide, a pair of T8s need a reflector 5" wide, a pair of T5s need a reflector 3" wide, a 70 watt MH needs a 6" X 8" reflector area and three HI LEDs occupy 1 square inch, we get the following:

T12: 16 - 18 L/in^2
T8: 24 L/in^2
T5: 37 - 40 L/in^2
T5HO: 69 L/in^2
MH: 100 - 125 L/in^2
HI LED .35A: 240 L/in^2
HI LED .7A: 420 L/in^2

Note that while it is theoretically possible to fit LEDs as densly as assumed above, there's a good chance that they would overheat that way. The commercial LED aquarium lights put them in at about 1/6 the density and use even less efficient LEDs (lower light output) to boot. So you could build an LED based aquarium light with the intensity listed above, but if you buy one, it's actual intensity will be close to a T5 HO or plain T5.

Also note that a square foot of LEDs at the density listed above would cost $2300 at today's prices, just for the LEDs. That's not even including the cost of current regulators and power supplies. LEDs last longer than fluorescents, but they don't last forever. They're expected to have lost a substantial fraction of their output at 50,000 hours.

In the aquarium hobby, we're usually limited more by how much area is over our tank, than by how much electricity we can deliver to it. So, if you could afford them, LEDs would be the best lighting choice for getting high intensity light in a small area. The next best choice (purely from a light intensity vs. area POV) is MH, and after that comes T5 HO.

The numbers above give a rough quantization of how the intensities compare.

Other factors we consider is the cost to buy the fixture and the cost of replacing light bulbs, but those types of numbers are readily available, so I won't bother with them here. 

Those rough light output and light efficiency numbers above should help folks compare different lighting choices.

Specifically, when we discuss watts per gallon, it gives a little better basis for talking about watts per gallon of T12 vs. T5 vs. MH lighting.


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## BryceM

Trag,

Great post. I'm curious about your LED info. I'd heard previously that their effeciency/watt was much, much better than the other light sources. Apparently you're saying that this might be possible someday, but that it is not true with currently available systems? There seems to be a discrepency between your info and what has been posted here previously.

Doing a little poking around on the web it seems that your info is fairly accurate. Hmmmm.

All of this still leaves us with a very limitted ability to recommend a certain "watt/gallon" ratio for a successful planted tank. Lumens aren't a great measure since they measure visible light, but not necessarily photosynthetically important wavelenghts. As far as a plant is concerned, what really matters is how much effective light energy a certain area of leaf is receiving at a given time.

Maybe watts per square foot (or per square meter) of tank footprint is a better measure.

Tank geometry and reflector design is enormously important too. Deep aquariums, elevated (pendant) lighting, and imprecise reflectors make a bad combination.


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## trag

guaiac_boy said:


> Great post. I'm curious about your LED info. I'd heard previously that their effeciency/watt was much, much better than the other light sources. Apparently you're saying that this might be possible someday, but that it is not true with currently available systems? There seems to be a discrepency between your info and what has been posted here previously.
> 
> Doing a little poking around on the web it seems that your info is fairly accurate. Hmmmm.


I was surprised as well. A year or two ago I got enthusiastic about LED lighting, but being of an engineering mind, I started looking into what is actually available. When one goes to manufacturers such as Luxeon (Lumileds) and actually reads the specs on the datasheets for their high output LEDs, you find that they are not any more energy efficient than fluorescent lighting. The marketing claims about incredible efficiency, must be in comparison to old incandescents or something. However, as I mentioned in passing, LEDs may get a bump in actual energy efficiency because they are somewhat more directional in their light emission than fluorescent or MH. In other words, they may emit about the same light per unit energy, but more of that light may actually reach the target.

LEDs are also not a cool lighting source. They produce a lot of waste heat. An LED fixture with a high concentration of LEDs would need to have a metal back acting as a heat sink and some fans to provide active cooling.



guaiac_boy said:


> All of this still leaves us with a very limitted ability to recommend a certain "watt/gallon" ratio for a successful planted tank. Lumens aren't a great measure since they measure visible light, but not necessarily photosynthetically important wavelenghts. As far as a plant is concerned, what really matters is how much effective light energy a certain area of leaf is receiving at a given time.
> 
> Maybe watts per square foot (or per square meter) of tank footprint is a better measure.
> 
> Tank geometry and reflector design is enormously important too. Deep aquariums, elevated (pendant) lighting, and imprecise reflectors make a bad combination.


It is a complicated topic. However, I think that if we used the numbers I gave above as rough conversion factors we can sort of recommend lighting amounts in terms of lumens--only they aren't really lumens....

Sheesh, this is hard to explain, but not really that complicated. What we care about, I think, is light intensity. Each person lighting a tank may choose a different spectrum of lighting (different intensities at different frequencies) depending on what their needs are. So we're never going to be able to do a perfectly equivalent job of specifying light spectrum and intensity--at least not in any way that is useful to most folks.

But, we can get in the ball park by using the conversion factors in my previous post. According to those numbers, 1 watt of LED lighting is equal to from 6/7 to 1 watt of T12 lighting. 1 watt of MH lighting is about the same as 1 watt of T12 lighting. 1 watt of T8 lighting is about 9/8 - 9/7 of 1 watt of T12 lighting. 1 watt of T5 HO lighting is about the same as 1 watt of T8 lighting or, again, 9/8 - 9/7 of T12 lighting. And 1 watt of non-HO T5 lighting is about 4/3 of 1 watt of T12 lighting.

Once you know how many watts are needed from one type of light, you can convert it to a roughly equivalent amount of energy input (watts electricity) in another form of lighting using the numbers above. Of course, with the caveat that the spectrum needs to be similar for the results to be similar.

So, for example, if 100 watts of MH works well on a 30 gallon tank, then 100 watts of T12 lighting would probably work about as well, if you can fit it on the tank top. But 75 watts of T5 or about 80 - 85 watts of T5HO or T8 would probably do about the same job.

Or a very practicle example...

I have a 30 gallon long (36" X 12" X 16"H) with an old light I built 20 years ago. The light consists of two 30 watt T12 bulbs. How much more light would I get if I switched to a pair of T5 HO 39 watt light bulbs? Well I'd have 78 watts vs. 60 watts, which is 1.3 times the wattage. But, using the conversion factors above, 78 watts of T5 HO is about equivalent to 90 - 100 watts of T12 light.

So a switch from 60 watts of T12 to 78 watts of T5HO would be about like increasing the light by a factor of 1.5 - 1.66, not the 1.3 that the simple wattages imply.


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## newbie314

My understanding is that white leds are not efficient at higher wattages and are better at lower ligh levels (this may only be due to not getting fluorescents to run really low wattage effieciently - the whole high voltage thing).
White leds operate by producing UV light and then it is flouresed into visible light (sound familar here). This is why LEDs tend to have a bluish hue to them.
The one advantage is the lifetime and ability to switch on-off alot. I don't know if the fluorescence would wear out on white leds.

The area where leds are efficient are colored such as red, and green. The reason being that normal bulbs create white (yellow) light and then are filtered to the desired color. Very inefficient. LEDs instead produce the color you want with no loss. Also again good at switching (long lasting), and the general lifetime. I.e. good for traffic lights.

I keep hearing about white led being more efficient in the technology publications and CNET etc, but no math. Those might be experimental or again low light level applications.

A church on the east coast (one during the American revolution with the lantern) is using white leds for highlighting the trim/ceiling. Again not too high of a light level, and better lifetime than other systems (hard to reach to change it).
http://www.cnn.com/2008/TECH/03/03/north.church.ap/index.html

For aquariums, I don't know what the spectrum would look like.
I know in the past before white led were avaliable people would combine red/blue/green/yellow etc to create a combined light that looks white. Again that would be for human eyes, wether the spectrum would be good for plants/fish etc would need further investigation.

Wikipedia quote "To produce a white SSL device, a blue LED was needed. In 1993, Shuji Nakamura of Nichia Corporation came up with a blue LED using gallium nitride (GaN). With this invention, it was now possible to create white light by combining the light of separate LEDs (red, green, and blue), or by placing a blue LED in a package with an internal light converting phosphor. With the phosphor type, some of the blue output becomes either yellow or red and green with the result that the LED light emission appears white to the human eye."
from the article http://en.wikipedia.org/wiki/LED_lamp

One led system is selling (expensive) and the idea is that one can have gradual light levels for the whole dawn, dusk, moonlight simulations.
Here's an example:
http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=18689&cmpid=03csegb&ref=3312&subref=AA&ci_src=14110944&ci_sku=0033919000000


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## nosoop4u246

In the not-so-long time I've been keeping aquaria, I have determined a few things with relative certainty. Cheif among them: any rules tried to apply to stocking and lighting will fail miserably. An aquarium is part art, part science, and when you try to take the part of art's domain into science, you run into trouble. The "inch of fish per gallon of water" rule gets thrown around a lot at lower levels, but quite clearly doesn't work (foot long fish in a 20 gallon tank should then be quite roomy), and neither does wpg, or any derivative of it. It might take 50 metal halide watts to grow a carpet of Glosso in a 30 gallon tank, but you could probably do the same with about 20 VHO T-5 watts. A watt is nothing more than an amount of energy used and in no way relates to the amount of energy emitted as light (case in point, incandescent bulbs), and cannot be converted into any rule, just as the length of a fish cannot be plugged into some formula (within reason) to determine how much space it needs, as there will always be a number of other factors (activity, agression, pH, temperature, maintenance, filtration, swimming level, decor, social habits) that alter it. To say a plant needs x wpg fails to account for how much water the light has to penetrate and over what span, the emission of the light, reflectors, the whole fertilization scheme, and basic parameters. I could put as many watts of VHO T-5 light over my 55 gallon tank as I want, but if I have don't have the CO2 and fertilizers to keep up, all I'll grow is algae. :idea:


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## hoppycalif

If I were just starting a planted aquarium I would have no idea how much light I needed. I would assume the light the tank manufacturer supplied with their tank would adequate, if barely so. But, beyond that I would be in the dark.

All that the watts per gallon "rule" is ever going to do is help people like me get somewhere in the right ball park for a good light intensity. Without that "rule" I would have to come to a forum like this, or, much worse, ask the LFS clerk what light or lights to buy. The answers I would get would range over a very broad spectrum, leaving me still guessing.

Knowing what I now know, I would aim for around 2 watts per gallon, using AHS light kits, in an enclosure similar to what AHS recommends on their website, and with that resulting fixture sitting on the tank. I would also realize that MH lights generally are available starting at 150 watts, so I would have little control over the watts per gallon, but I could always use those lights suspended above the tank far enough to limit the light intensity as I wished.


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## Newt

Color spectrum and lumens does not equate for plants. The majority of plants do not utilize green light for photosynthesis. A higher lumen rating at the same wattage often means greener light. Lumen is a rating weighted entirely towards human perception. It has little to do with the value of a light for either growing or viewing plants.

Lux is lumens/square meter, so they are similar. They are both defined in terms that are meaningful to human perception of light – not plants. They stress the amount of energy in the green band to which humans are most sensitive – not plants. 

Artificial light sources are usually evaluated based on their lumen output. Lumen is a measure of flux, or how much light energy a light source emits (per unit time). The lumen measure does not include all the energy the source emits, but just the energy with wavelengths capable of affecting the human eye. Thus the lumen measure is defined in such a way as to be weighted by the (bright-adapted) human eye spectral sensitivity.

The standard measure that quantifies the energy available for photosynthesis is "Photosynthetic Active Radiation" (aka "Photosynthetic Available Radiation") or PAR. This is blue and red light. This is why it is so important to get the spectral output of a bulb before deciding if is a 'good plant light'. 

Watts is also another term you need to be careful with. You can have 400 watts of lighting but if its not putting out light that plants can utilize its worthless. The bulb could have a relatively flat spectral output with little or no light usable by plants with very little intensity in the blue and red and a large green spike. So where are the watts going?>>>>>HEAT and an ugly green hue to your tank.


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## yves2013

i am wondering about my tank it is a 10g tall tank, my hood is only equipped for one fluorescent bulb. i have a "t5 8w, power-glo" bulb in there... is that enough? do i need more?


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## hoppycalif

8 watts is far from enough to grow almost all plants in a 10 gallon tank, even one with standard depth. With the extra depth (17 inches?) of that tank it will be difficult to find a light fixture that will work well. One that might do it is a pendant MH fixture, preferably a 70 watt one. You would have to operate the tank with an open top to use that.

You could grow mosses, perhaps anubias and ferns and crypts with that light. If you aren't particular about what plants you use or how slowly they grow it might work fine.


----------



## newbie314

You'd need a minimum of 20watts if doing an "El Natural" setup.


----------



## Ljeto

I just finished my new top, with 6x80w T5. The tank is 375L, 150x50x50cm. Now, for the first two days, I am like a kid with a new toy. Everything is pearling, glosso is taking off, but so are the aglae.
I use presurised co2, add micros and macros, though not very precisely.


----------



## Outsane

ODNA Eclipse 3 hood for 29 gal tank

the hood takes two 24" T8

what would be a good bulbs to get?

I saw phillips plant bulbs at home depot, just not in 24" T8


----------



## Peter16

I am running a 20gal long, with 2 24watt t5ho bulbs in it and diy c02.

Would this be enough combined with flourish and other ferts to grow some half decent glosso ? as well as other stem plants requiring moderate lighting.


----------



## lizziotti

Peter16 said:


> I am running a 20gal long, with 2 24watt t5ho bulbs in it and diy c02.
> 
> Would this be enough combined with flourish and other ferts to grow some half decent glosso ? as well as other stem plants requiring moderate lighting.


I know this post is old but I came across this on my search for the same ?

I have a similar setup and have been wondering the same thing. Does anyone have an answer? I've also wondered if DIY co2 is enough with this lighting?


----------



## anhtu402

Lizziotti, 

I am currently running a 29 gallon setup, with a 55W Power compact, DIY CO2 & Glass Diffuser from Ebay. The glosso I bought was less than a month ago, and with that simple setup and some fertilizing with Excel, I was able to cover 3/4 of my foreground with probably 20 or so glosso I bought from a member from here. 

All in all, I think your setup should be able to grow those glosso...if I can do it (I am pretty much a newb at this new hobby), I am pretty sure anyone can do it! Good luck!


----------



## houseofcards

lizziotti said:


> I know this post is old but I came across this on my search for the same ?
> 
> I have a similar setup and have been wondering the same thing. Does anyone have an answer? I've also wondered if DIY co2 is enough with this lighting?


Your lighting is fine, but remember not every 20g is created equally. You need to stay on top of your DIY co2 as well as ferts. Substrate will also play a role in how much you need to fertilize.


----------



## Peter16

well i have pressurized co2, the lighting mentioned above, excel, and a half decent substrate (i think) so i will see how i go.


----------



## Laconic

I use 3 x T8 38w (2 x Arcadia Freshwater Lamps and 1 x Original Tropical) for my 48x18x20 Tank (~75 gallons). That amounts to about 1.6 wpg, which by most conventional measures is quite low. I use pressurized Co2.

I have no problems growing fairly light demanding species such as Eriocaulon Cinereum and C. Parva. While I do not get pearling, or intense red colouration, I believe it is indicative that the WPG rule ought to be taken with some caveats. As a quick and dirty measure, it is adequate but definitely it is not the be all and end all with regards to lighting.


----------



## brownietrout

i have a 55 gallon with diy co2 and 2 coralife-65w 8000k compact florescents.
My plants are growing well but I don't get pearling, which I would love to see, and the colors are not showing the red I would also like to see.
Any suggestions on how I could improve my light output without buying new fixtures at this time.


----------



## Newt

brownietrout said:


> i have a 55 gallon with diy co2 and 2 coralife-65w 8000k compact florescents.
> My plants are growing well but I don't get pearling, which I would love to see, and the colors are not showing the red I would also like to see.
> Any suggestions on how I could improve my light output without buying new fixtures at this time.


Get bulbs other than Coralife. They all have way too much green in the spectral output.


----------



## brownietrout

opps. I have 2 coralife fixtures with 2-AGA-8000k full spectrum compact flourescents


----------



## mudboots

I looked into the thread on PAR vs WPG and my numbers just don't quite add up with regards to wpg recommendations. I put the numbers on that thread, but as far as this thread goes, I have a 20 npt with 2.5 wpg T5HO (2x24w) with no problems growing stems, and a 125 npt with only 1.25 wpg T5HO (4x39w) with no problems growing stems except in shaded areas (some Rotala bit the dust after a 1 week bout of pea soup). I have to mention though that these set ups are pretty new, so I don't have long-term observation to confirm how well everything is doing. They have been set up about a month or so.


----------



## popomon

honestly, i couldn't read everything  But i would have to say that 108 watts t5ho on a 55 is sufficient. My plants are all green and healthy, and one of my bulbs is an actinic. i think its more on the ratio of ferts to light to co2 because if i had more light with the same low lvl of co2, it wouldn't do anything. Plus, i thought t5ho lights had better water penetration than CF? wouldn't that make it better for deeper tanks? mainly since i've heard that t5 bulbs have more blue light compared to CF and others, except for halide and stuff. Dont pin me to that though  Im still a beginner


----------



## Seattle_Aquarist

Hi popomon,

I have to remind myself sometimes that it is a light "system" and the bulb is just a part of the system. The other part is the reflector. A T5 bulb and a CF bulb are basically the same; however the CF bulb is bent into a "U" shape. A T5-HO bulb is a high output version of the T5/CF bulb.

I have found that the quality of the material in the reflector (i.e. MIRO 4), and the shape of the reflector, make a huge difference in the ability to get a good level of light down into the aquarium where the plants are, especially down to the substrate level.


----------



## popomon

oh, well that sucks  I think i have a single piece reflector on my dual bulb coralife, still gets the job done though so it aint too bad


----------



## OVT

Oh boy, here we go again. In short  I'm working on a brand new set-up: 48 x 18 x 18 open top glass tank with some hopped-for emersed growth. I spent about a week full-time doing research on the web and talking to friends in the hobby. Lo and behold, you've guessed it, the only major piece left is lighting.

And I am *totally clueless* on what I need and/or what I want.

At the moment, all 3 of my existing tanks have Coralife CF fixtures: 4 x 65W over 24" tall 75G, 2 x 65W over 20" tall 37G corner and 1 x 96K quad over 18" tall ~24G "nano cube" knock-off, all with 6700 Coralife bulbs. All tanks have the same pH, kH, gH, TDS, nitrates, Fe, substrate, similar plants, bio-load, ferts, temperature, water changes, filters, no co2 except Excel, etc, etc, etc. And all tanks are doing differently. The nano-cube is doing the best: I can grow anything, no algae. 75G now has diatom issues on swords (10 year-old tank), and the corner 37G is a constant maintenance headache. Feels like 1 out of 3 is always out of whack and they are taking turns every 6 months or so. (1 out of 4 would make a better ratio ).

And for the life of me I am hard pressed to find or to understand the correlations or dependencies. (Must be the reason why I stay with the hobby).

T5HO? CFs? MH? LEDs? Watts? Lumens? PARs? 10K? More red or blue? $50 at HomeDepot or $795 at on-line retailer.

Fun. Back to my spreadsheet.


----------



## popomon

> Oh boy, here we go again. In short I'm working on a brand new set-up: 48 x 18 x 18 open top glass tank with some hopped-for emersed growth. I spent about a week full-time doing research on the web and talking to friends in the hobby. Lo and behold, you've guessed it, the only major piece left is lighting.
> 
> And I am totally clueless on what I need and/or what I want.
> 
> At the moment, all 3 of my existing tanks have Coralife CF fixtures: 4 x 65W over 24" tall 75G, 2 x 65W over 20" tall 37G corner and 1 x 96K quad over 18" tall ~24G "nano cube" knock-off, all with 6700 Coralife bulbs. All tanks have the same pH, kH, gH, TDS, nitrates, Fe, substrate, similar plants, bio-load, ferts, temperature, water changes, filters, no co2 except Excel, etc, etc, etc. And all tanks are doing differently. The nano-cube is doing the best: I can grow anything, no algae. 75G now has diatom issues on swords (10 year-old tank), and the corner 37G is a constant maintenance headache. Feels like 1 out of 3 is always out of whack and they are taking turns every 6 months or so. (1 out of 4 would make a better ratio ).
> 
> And for the life of me I am hard pressed to find or to understand the correlations or dependencies. (Must be the reason why I stay with the hobby).
> 
> T5HO? CFs? MH? LEDs? Watts? Lumens? PARs? 10K? More red or blue? $50 at HomeDepot or $795 at on-line retailer.
> 
> Fun. Back to my spreadsheet.


lololol, i'll give you a rundown of my basic knowledge 

wattage can't give a reasonable estimate anymore. for example, 
6 wpg over a 10 gallon with incandescent bulb puts out as much light as 1.3 wpg over the same tank with a fluorescent bulb, because fluorescents can put out more light for the wattage. now, t5ho, t5, t8, im pretty sure, are all a type of fluorescent, but in a large scale, still have their own "ratings". So i would say that a t5ho, can not only put out more wattage than a standard t5, but is classified more efficient for the wattage as well. also, plants like lots of red and a mid amount of blue in the light spectrum, stuff we can't see, as a 6700k bulb from different manufacturers may produce the same visible light to us, they may have different levels in the light spectrum. I've heard of diversity within the same brand, as the common 50/50 bulbs and cfls from coralife have more green in the spectrum (useless) but on my spectrum chart for my t5ho bulbs (also by coralife), they had almost no green, and mostly red and blue. So its a luck game. going back to the subject of wattage efficiency to light usability, LEDs are once again at the top. Although many commercial LED systems are "dimmer" than the standard lighting for the recommended tank size, if you were to ramp up the wattages equal to each other, the LED light would easily destroy the competition, and not only can it give out more light for it's wattage, i've heard that LEDs also have more usable light as a vast array of different particular spectrums and LED sizes can be incorporated into one big unit. remember, energy can be neither created or destroyed, so the right off the bat, you can tell that the light sources that give off less heat are putting more energy into the actual light. Lumen output usually effects the usable light, as it can help determine that number, but im not personally 100% sure.


----------



## OVT

Ended up with Tek T5 6x54W 5" above the top of a 18"-deep tank. My new algae by mail business should be in full production soon


----------



## popomon

sheesh, 300 watts for a 75 gal? thats quite a bit sir  4wpg is very unstable unless you can keep a very strict fert and co2 regiment going. But if you do get the co2 and ferts right you've got yourself a tank that can grow anything haha. Maybe if you overdose excel until the "experimental" phase of co2 is over, you can remove the chances of ever starting with algae which will help in the long run


----------



## JakeJ

But what about reflectors? You could have a 20w T5HO fixture on a 10g, and still only have low/medium light. This "rule" in my opinion is very incomplete if you will and inaccurate. The amount of photosynthetically active radiation that reaches the substrate is much more accurate, as it takes into account the reflections that go on inside the tank and fixture. Check out Hoppy's thread over at TPT forum. He has it down.
Regards,
Jake


----------



## dobie832

JakeJ said:


> The amount of photosynthetically active radiation that reaches the substrate is much more accurate, as it takes into account the reflections that go on inside the tank and fixture. Check out Hoppy's thread over at TPT forum. He has it down.
> Regards,
> Jake


There are some fundamental errors in his theory which need to be corrected. Otherwise decent thread.


----------



## jerrybforl

What do you guys think about T-8s 2x32watts over a 29 gallon 30" long. I think its 18" deep. I want to grow high light plants in it. I have a 75gallon with PC on it and CO2 with 4x65watts on it.


----------



## popomon

thats only about 2wpg though. maybe add another bulb?


----------



## bif24701

I have Aquaticlife T5 HO 4x24 watts (2x6000k and 2x 650nm Roseate) with individual highly polished reflectors over a 36g bow front. Seems to do well. I use Seachem Flourish and DIY CO2, soon to be press. Just upgraded so will let you know how it does.

How long should I time the photo period? I can set timers on a pair of bulbs individualy. Right now it is set for one set (6000K and 650nm roseate) for an hour in the morning and evening before night. Then 10 hours of full power (4x24). What do you think?


----------



## Newt

bif24701 said:


> I have Aquaticlife T5 HO 4x24 watts (2x6000k and 2x 650nm Roseate) with individual highly polished reflectors over a 36g bow front. Seems to do well. I use Seachem Flourish and DIY CO2, soon to be press. Just upgraded so will let you know how it does.
> 
> How long should I time the photo period? I can set timers on a pair of bulbs individualy. Right now it is set for one set (6000K and 650nm roseate) for an hour in the morning and evening before night. Then 10 hours of full power (4x24). What do you think?


With T5HO it might be too long but if you arent having any algae issues I'd say OK. You may find you need to cut back to a max of 10 hours or even 8. Good idea with the stepped up/stepped down senario.


----------



## captmicha

Why does the intense lighting require C02 supplementation?


----------



## yckelvin

Many thanks for your information, John N. It is very useful. May I confirm the gallon is in UK or US unit? 

My tank is 24"W x 18"H x 8"D and 55L, now using 3 x 16w T5 HO 13000K (28.83cm length), is that enough for plants?

Kelvin


----------



## ray-the-pilot

captmicha said:


> Why does the intense lighting require C02 supplementation?


I don't think anyone knows for sure why or even if this is true but it is commonly thrown around as a potential cause for algae growth.
I think the theory is that if plants get what they need in a balanced way, then algae will stay at bay. If something is out of balance, the higher species of plants don't grow as well giving algae an opportunity to proliferate.
So higher light requires more nutrients to stay in balance (ie CO2 supplementation).


----------



## NursePlaty

Right now my 55g has 92 watts from 4x23W 6500L CFLS. Should I increase 4 bulbs? total of 8 bulbs?


----------



## fishyjoe24

NursePlaty said:


> Right now my 55g has 92 watts from 4x23W 6500L CFLS. Should I increase 4 bulbs? total of 8 bulbs?


what type of light are you trying to get? low,med, high? depends on what you want to grow.
I got medium light over my 29g with just 36w of t5 bulbs. just 2 t5 no bulbs got me medium lighting. :twitch: it's all about p.a.r., and lums in my opinion. also not all bulbs are created equal. I like ati and uv. coralifes are good but on the lower end. also are your plants growing? don't fix it unless it's broken.


----------



## NursePlaty

Wanting to get high lighting. Everything is growing fine but I want my plants to look their best. I want the reds to be more redder and stronger light so it can penetrate to my foreground plants. Chart showed 108-200 or something like that and I was only at 92. I also wanted to grow HC and I don't think I can achieve that with only 4 CFLs 23w each.



fishyjoe24 said:


> what type of light are you trying to get? low,med, high? depends on what you want to grow.
> I got medium light over my 29g with just 36w of t5 bulbs. just 2 t5 no bulbs got me medium lighting. :twitch: it's all about p.a.r., and lums in my opinion. also not all bulbs are created equal. I like ati and uv. coralifes are good but on the lower end. also are your plants growing? don't fix it unless it's broken.


----------



## Cachimbo

Hello,

Wattage for aquarium confuses me a bit. How much is too much or enough?

Well, I have a 50 Gal, 20" tall, two T6 AH Supply 96w compact, 6700K. That is 3.84w/Gal. can alternate the tubes and have 1.92w/Gal. Tank is medium planted on its way to heavily planted, and just finished cycling. Soon I will install injected Co2 (actually have DIY).

I have read about T8, T5 an so on but the wattage rule does not partner for each type of illumination.

Is T6 3.84w too much? I am new at this, please someone get me out of my confusion

welcome any comments [smilie=b:


----------



## ray-the-pilot

Cachimbo said:


> Hello,
> 
> Wattage for aquarium confuses me a bit. How much is too much or enough?
> 
> Well, I have a 50 Gal, 20" tall, two T6 AH Supply 96w compact, 6700K. That is 3.84w/Gal. can alternate the tubes and have 1.92w/Gal. Tank is medium planted on its way to heavily planted, and just finished cycling. Soon I will install injected Co2 (actually have DIY).
> 
> I have read about T8, T5 an so on but the wattage rule does not partner for each type of illumination.
> 
> Is T6 3.84w too much? I am new at this, please someone get me out of my confusion
> 
> welcome any comments [smilie=b:[/QUOTE]
> 
> I'd say you are OK the rule of thumb used to be 4 watts per gallon. So you are in the ball park.


----------



## Skelley

I have been reading and reading, here and everywhere else. Depending on where I look it seems I have either high light or too much light. However my hairgrass is growing up instead of out and is starting to look pretty rough. No pearling anywhere.

I have 2 T5HO 24w 6500K bulbs about 4in above the water on a 36g, about 17in from surface to substrate. The unit will allow me to put in 2 more bulbs. I am toying with throwing in another bulb, but of course I am uncertain if I already have too much light. I would like to be in the 3wpg-ish range.


----------



## Cachimbo

Hey guys,

I found this info maybe it could be helpful. It definitely clarified several things about aquarium lighting. What I learned is watts per gallon not merely defines how much light is needed.

http://www.americanaquariumproducts.com/Aquarium_Lighting.html


----------



## brokefoot

I just posted a new thread with an Aquarium Lighting Calculator spreadsheet I came up with. It uses tank dimensions and Lumens per Watt figures to estimate Lux at the bottom of the tank. And it gives ranges for "Very Low" - "Very High" light levels. It would be great if some peole could test it against their systems by posting dimensions, bulbs/wattages & their perception of the light levels they are getting.

I know Lux is not as good as PAR and the calculator can't take into account all factors, but it is a very quick estimate that should be much, much better than Watts per Gallon and doesn't require a meter or manual calculations.

Thanks for any input!


----------



## Jaap

So I found out that I have two 4 Pin PLL 36W lights with reflectors just like this one http://www.lightbulbs-direct.com/pro...ht-2g11-4-pin/ over a 90L tank 58 cm in height. How does that sound?


----------



## brokefoot

hadjici2 - I had not heard of PLL lights, but from what I found searching online it is a T5. The only lumens/watt figure I saw for PLL was 91 l/w. 

When I plug stardard 90G tank dimensions into my calculator it says you are below even "Very Low" light. Do you currently have any plants growing in the tank?


----------



## Jaap

brokefoot said:


> hadjici2 - I had not heard of PLL lights, but from what I found searching online it is a T5. The only lumens/watt figure I saw for PLL was 91 l/w.
> 
> When I plug stardard 90G tank dimensions into my calculator it says you are below even "Very Low" light. Do you currently have any plants growing in the tank?


It is 90L not 90G.


----------



## brokefoot

Sorry. I've got you at the low end of "High Light".


----------



## Jaap

Would this lighting fixture be adequate for a 90L aquarium 60cm height? To grow DHG with co2.

Ebay number: 260833089112 
NEW 48w 24" aquarium light 2 feet fixture T5 HO lamp


----------



## DaveFish

I have 140 watts of T8 lighting over my 55 gallon. 2-6500k 30w with 2700 lumens. 2-18,000k 40w with 1850 lumens. From base of lights to substrate is 22" the lights sit a few inches above the tank. Where would my lighting be on your scale? I am adding pressurized co2. Is my lighting efficient enough or am I wasting my co2? Thank you.


----------



## gladiator008

beginner >>>>I need help i have anubias and java fern in a 85 gal. tank what type of wattage would anyone suggest that i use?


----------



## debisbooked

eklikewhoa said:


> Oops, new I forgot something.
> 
> 96w 6700k quad bulb coralife fixture on coralife legs
> Open top tank
> Photoperiod of 8hrs
> 
> Thanks for the comment john!


I have a Coralife 65w resting on the versa glass. Currently I am growing low light plants. I was thinking of getting the 96w coralife fixture. Are you using co2 with that?


----------



## lilobee

Reading this hurt my head... bring the pain! (o:


----------



## Miguere

Hello, I just need to know for how long you run your light? How hi is from the aquarium ?


----------



## TropTrea

I have just joinded this group and browsed through this thread for the first time. I had had a lot of experience years ago with planted tanks and recently with reefs. An interesting here is a very common question being how many watts do I need of light. From my experience this is very clumsy way of looking at the lighting. 

Compact Florescents were the crave when I had my last planted tanks. They have a great advantage over the old T-12's as they have a lot more wattage of light in a shorter amount of space. However if you actually measure efficiency in the form of PAR at the Substrate per Watt of power your lighting fixture produces you will find this is not always true. The problem with the Compacts are that design makes the use of reflectors less efficient than a straight tubed light. 

Simularly even with old standard T-12's there was a wde range in the efficiency based upon the design of the lighting fixture. Going through the years you had white solid reflectors that were less efficient than polished aluminum reflectors, You also had individual reflectors for each bulb that were shaped in different ways varying the degree of there efficiency.

The next big move was to the T-5 bulbs that allowed more air space between bulbs allowing the efficiency of the reflectors to increase even more so. It is very easily possible to have a twin bulb 80 watt fixture with T-12 bulbs which gives you a PAR of 50 at the substrate level and another twin bulb 80 watt T-5 fixture that could give you 75 par at the substrate. 

the next big advance in lighting comes with HO-T-5 bulbs. These are special designed T-5 bulbs that are designed to run at roughly 1/3 higher wattage than the conventional T-5 bulbs. The light output when compared on a per watt bases bases is also usually slightly higher but this is not always true. There is today a big difference between different bulb manufacturers on these bulbs and you can almost say you get what you pay for in most instances.

You also have numerous other things that fall into the equation. Par is nice means of measurement but it is only slightly better than Lumns. Fresh water plants need blue and red light in the photosynthetic frequencies for growth. But PAR includes all the wave lengths including many to the mid wave lenghts that are not utilized for photosynthesis. Similarly light sources like 18,000K or 20,000K are noit benifical for plants as they produce the blue light they need but produce close to no usable red light that they require. 

Moving on you have other variables like which plants you have as well as how clear the water is. Some more acidic tanks will hold a yellowish tint from tameric acid that reduces the light getting to the substrate. 

I personally cannot see a simple formula for determining the light requirements. Yes you can get into a rough range but you also have to do a lot of experimenting to see what works best in your situation.


----------



## Newt

PLL is a biax bulb aka Power Compact or Compact Fluorescent.
Typically used with Philips made bulbs as part of the model ID.

They can be approx the same diameter as a T5 but are not considered high output as in T5HO.


----------



## TropTrea

gladiator008 said:


> beginner >>>>I need help i have anubias and java fern in a 85 gal. tank what type of wattage would anyone suggest that i use?


In my last planted tank I was using 120 Watts T-12 lights, 80 Watts of GE 6,500K and 40 Watts of GE Chroma on a 75 gallon tank. This was with a CO2 system that was not extremely efficient. At the time I had 3 different strains of anubias in that tank but they were partially shaded by many Amazon Sword plants in that tank. The lights were sitting on top of an Acrylic top that I had constructed.


----------



## TropTrea

John N. said:


> - John N.




Sorry but I think these lighting levels are extremely high for planted tanks especially when your looking at the larger tanks. I have had 8 54 T-5's on a 120 Gallon reef where I was keeping some of the highest light demanding corals around. With a good fixture and a the lights low this gives more than 200 PAR at the substrate.

But yes a chart like this could create a rough guide for the beginner or even the intermediate individual looking at setting up a new tank. However the chard needs to produce a rang of low light, medium light and high light to cover the range of light used by different plants. Also it would be good to add a column for the old T-12 Florescent as they are still used by many as well as marketed in fixtures of up to 4 tubes. And last but not least LED lighting that I believe will make most of the florescent lighting obsolete in a few years.

There is only one big problem with setting ranges on LED's and that is the difference between LED's out there. You can purchase a LED that gives less then 75 lumns per watt or one that gives over 120 lumns per watt today with the same K rating. The industry is also claiming they will be exceeding the 200 lumns per watt range in less than a year.


----------



## Thoughtsprocket

Hi Everyone,

I'm looking to upgrade my lighting situation for my 20 gallon tall pressurized co2 tank. I've been saving the bucks to do it. If I understand the graph up there in this thread I should purchase a fixture with two T5HO bulbs that are 24 watts. Does that mean 24 watts total or for each bulb?

Can anyone tell me which fixtures and bulbs they've purchased for their 20 gallon and the positives and negatives about them? I'd prefer to have the new fixture sit on top of the tank....just an FYI. But will definitely consider light hanging above the tank, if that's a best solution.

Helpful Info:

20 Gallon Tall
Ph 7.4
Ammonia 0
Nitrates 10
Nitrites 0
Pressurized Co2, 2-3 bps, and 1hour daily siesta
Eco-complete substrate
Modified HOB filtration system ( adding one more of same)
Fully planted and thriving although a bit yellow and elongated from too low light.
Root Tabs paired with swords (Just ordered Flourish Tabs instead)
Leaf Zone Fertilizer in water column


----------



## ray-the-pilot

Thoughtsprocket said:


> Can anyone tell me which fixtures and bulbs they've purchased for their 20 gallon and the positives and negatives about them? I'd prefer to have the new fixture sit on top of the tank....just an FYI. But will definitely consider light hanging above the tank, if that's a best solution.


You are wasting time and money buying anything less than a LED fixture.
The good news:
OK I have one of these "just sitting" on a 20 gal reef tank and it puts out more than 400 PAR at the substrate. Since it is dimmable I run it at 40% with a diffuser that reduces the light down to 65 PAR. 
http://www.amazon.com/TaoTronics-TT-AL09-Dimmable-Aquarium-Lights/dp/B0092LXQRM

The bad news:
They are out of stock.
There are a lot of similar fixtures but I cannot recommend any.


----------



## TropTrea

ray-the-pilot said:


> You are wasting time and money buying anything less than a LED fixture.
> The good news:
> OK I have one of these "just sitting" on a 20 gal reef tank and it puts out more than 400 PAR at the substrate. Since it is dimmable I run it at 40% with a diffuser that reduces the light down to 65 PAR.
> http://www.amazon.com/TaoTronics-TT-AL09-Dimmable-Aquarium-Lights/dp/B0092LXQRM
> 
> The bad news:
> They are out of stock.
> There are a lot of similar fixtures but I cannot recommend any.


That fixture is 165 Watts. I can see where you have it at 40% power for roughly 66 watts of power. But even at 66 watts of power if it really is using efficient LED's it would be on the bright side for anything under 60 Gallons.


----------



## ray-the-pilot

TropTrea said:


> That fixture is 165 Watts. I can see where you have it at 40% power for roughly 66 watts of power. But even at 66 watts of power if it really is using efficient LED's it would be on the bright side for anything under 60 Gallons.


Seriously! Maybe you didn't read the part where I said it was at a "measured" 65 PAR in a 20 gal tank! 
Now if that is too bright for you, what can you do? 
1. Set it down to 20% (increase your already super long life) 
2. Raise the fixture up 6 - 12 inches. 
3. Add a second diffuser. 
This is on a fixture that I purchased for $120. (BTW I have three).

Now if your fixture *doesn't* produce enough light, what can you do.
1. Buy another one and use two (or more).
2. Get a better fixture.


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## annak

Hello, I am starting a Walstad method tank, no CO2. It is 7.5 g 40x26x30. Will 2 CFL 11W 6500 be ok according to wpg? A pet shop owner told methat it's going to be too much and I'll get algae for sure. What do you think?


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## Michael

Annak, this sticky thread is very old and most of the information is outdated. That said, I still use a few CFLs over my Walstad tanks until they burn out. From my experience, I suggest just one 11W CFL over your tank, but keep the possibility of adding another one later.


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## annak

Michael thanks a lot for your reply! I wasn't sure about wpg and thought that maybe for this area one wouldn't be enough so I ordered two CFLs. I'll start with one and see how it goes!


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## TropTrea

Wow I have not been here in some time. So a little update on what I currently running. My main tank now is the 120 Gallon tank where I'm running my newest LED fixture. It consists of 12 Watts of Blue LED's, 8 Watts of red LED's and 4 Watts of Neutral whit LED's that I run for 14 hours every day. Yes it does give a purplish hue which is why for 6 hours when I view the tank the most I add an additional 12 watts of Warm White, and 8 Watts of Cool White LED's. I had run with just the lights from the 14 hour cycle for about a year without adding the added whites and there was good plant growth with very little growth difference from when added the whites. 

This is a 120 gallon tank without CO2, And I do 20% water changes weekly then add liquid fertilizers that that I mix with each water change, and use root tabs for my Amazon Swords.

Plaese not for the watt people that I'm basically using 24 watts on a 120 gallon tank with is roughly 1/5 watt per gallon. and even with the added whites I still under 2/5 watt per gallon


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