Look on Ebay, buy 5 metre waterproof LED strip along with transformers. All you have to do it connect the two wire ends which is easy enough with a twist tie and doesn't require any soldering. Stick it to the underside of your hood, plug the transformer into a plug-in-timer, easy, done, cheap.
I'd recommend the 5050 super high-output high-efficiency ones which have 60 diodes per metre (or secondly the 3528), to give you 300 LED diodes per 5m spool. (They're not as high output as CREE's but they also don't run as hot and therefore don't require a heatsink(. A spool with transformer will run you about $60. Some of them are listed at producing 400-450 lumens per metre (or 7 lumens per diode), and consuming 14.4 watts per metre. They're not as bright as Crees, but if it's the same cost and efficiency to use hundreds of these as it is for a few dozen CREE's then that's rather irrelevant.Anyone have any idea how that compares to say 2 florescent watts per gallon though? The 5050's are supposed to last 10,000 hours, and I think I read that they're still producing more than 90% of their rated output after a year, which is far superior to any other type of lights inluding florescent.
I have a combination of warm-white and cool-white on my tank. I prefer the look of the warm-white much better, but have it combined with cool-white for now. I'm not exactly sure which one is better for plants, but having seen the spectral analysis for each, they both seemed to have a decent spectrum to cover the appropriate necessary wavelengths. They had similar light output across most of the spectrum but the cool-whites have an enormous output spike in the bluish range. I'm testing this out on a small tank right now myself, while I'm planning out a larger 200-300 gallon tank. For that tank I know that to achieve 2 watts per gallon, I'd need 5 spools, but as those are LED watts instead of florescent watts that might still be overkill. I had an Ecoxotic Stunner Strip on my small test tank, but took it off as I actually prefer the LED strips I bought myself no Ebay.
The Spectral Graphs for standard warm white and cool white LED's are at this link - http://www.superbrightleds.com/cgi-b...pcool_warm.htm
And I'd heard the following:
Plants have two types of chlorophyll: A and B. Chlorophyll A absorbs light at 405 and 640 nm. Chlorophyll B has peak absorptions at 440 and 620 nm. Plant lamps are designed to emit light at red wavelengths to duplicate the light of the sun, but too much red color can cause aquatic plants to grow tall and thin. For best results, use a daylight (5000K) lamp in combination with an actinic white or actinic day lamp.
But I'd also seen statements elsewhere which use slightly different numbers, and it's obviously not as if plants only use a single wavelength of light. I'd also seen 420 mentioned as the peak absorption point for chlorophyll A, and that chlorophyll can use light from 400-550 nm and 650-700 nm. So perhaps we all need to look at this matter a little more closely.
In any case, LED lights do provide some light in the red and blue parts of the spectrum which plants utilize. Personally, in terms of how it made the tank itself look, I prefer warm-white over cool-white, or at least a combination of the two. It would be easy enough as well to add some supplementary bars or strips of red, blue, and/or ultra violet LED's to provide some additional coverage at those points in the spectrum, but you probably would not want to make that the predominant lighting in your aquarium as it might make it look a bit funny. You can inexpensively get 5 metre spools which have alternating red, green, and blue LED's even, and they have some of those that are controlled by remote controls so you should be able turn off the greens if your plants aren't going to use that and if you don't happen to like the look of your plants looking intensely green!
As for myself, I just received my latest supplementary LED lights, which include small wands of Red and Blue, but I'm yet to have a chance to attach them to my hood to see how they look. I'm thinking that perhaps I should have tried to find a wand of ultra-violet as well though.
I'm actually going to be working with a lighting designer shortly to light almost my entire house extension indirectly with warm-white LED's hidden in alcoves, so I'm confident they are up to the task of lighting a tank, if you use enough of them. With each, that would give you 300 individual LED diodes, and it's not as if the photons from LED lighting are different than the photons of any other lights, in contrast to what some had practically suggested elsewhere (in suggesting LED light won't penetrate as deeply).