Hate to tell you guys this but lenses are counter productive for growth because it causes light to saturate specific chlorophyll paths in the plant while starving others. Not to mention it causes terrible shadowing under the leaves. If you're ever sat in a lawn chair on a sunny day for a few...
True, but the actual phosphor formulas and ratios are pretty much the same. Fluorescent tubes typically use a mercury based UV plasma to excite secondary phosphors in various ratios to provide color. The more colors used in the spectrum to increase CRI the lower the efficiency of the tube...
Gonna throw some science stuff in here because that's what Cave Johnson would do...
Anyways, fluorescent phosphors are fluorescent phosphors. Doesn't matter if it's a T5, or T8, or a fatty T12 or a CFL. Doesn't matter.....almost identical spectrum per kelvin temp and CRI category.
There are...
20,000k means it's going to be throwing almost all of it's energy at around 455nm, which is deep blue. Good for corals, but for purposes here you want the lowest kelvin bulb as possible. Metal halide goes to about 3200k. To get any redder you need to move to HPS - different ballast I believe...
Can I honestly ask why most of you just don't build your own LED fixtures and save a lot of money? Seriously, I've been doing this myself for about a year now, and can hit that same PAR (photosynthetic active radiation) values as the HydroGrow for about 1/4 the price using Crees and knockoff...