you people trying to compare LED lights from the to the other, using 2 plants per light and shit... your not doing it right at all...
You would need to do a minimum of 5 plants per light, and record dry weight for those plants ALL THE same strain, then do a statistical analysis using T-test to compare the means... you cant just say
51 gram blackstar
41 gram other light
for 2 plants a light, just doesn't work like that.
I don't really agree with you there, I think growing 5 plants under a Blackstar 240w is unreasonable as it just doesn't have the coverage for 5 plants. I agree that there are better ways to test but in general it was a decent comparison considering the same strains were used, same environmental conditions, same nutes and both grows were sectioned off from each other. This experiment gave some decent information regarding LED growing in general. What I got from the test is:
Maybe more coverage has a bigger impact on yield then higher wattage in a smaller area. This Light show down was between a 133w panel and a 244w panel and 133w panel was shown to be more efficient in the gram to watt department.
Now take a look at the 244w panel, it is physically bigger then the 133w panel by 1/3rd and it's yield was 1/3rd more so this raises some very important questions.... Was the yield larger because of the size/coverage or because it was a brighter light? I think we can agree that this is worth looking into and can change the way we think of growing with LED lights.
@ColoradoLove: Of course the 244w panel produced bigger yield then the 133w panel but the interesting part is that it didn't beat it by much for running nearly double the watts, You can buy 3 of the 133w panels for the price of that spectra 244w light and that is where the value and strength is in that light...running them in groups.
For the record I am currently running a Blackstar grow but am using seeds from a local outdoor strain until my order comes in so I am deciding if I should do a journal now or wait for my proper strain. The seeds I am working with are old and the germination rate is horrible but I do have 3 strong seedlings and if I can get another 3 to flourish I will just start a journal to share the LED data. I'm convinced that using a crazy light soil mix is key when growing with LED's (thats if you grow with soil) and I will be experimenting with panel height which should provide some good data as well.