Well, T8 bulbs aren't very powerful, something like a T5 fixture will have more watts and output more lumens. What plant or plants did you have in mind?
So the funny thing is, the watts per gallon rule doesn't really apply to newer bulbs, only T12s, because a T5 could have the same wattage as a T8, but it outputs way more lumens or units of light. The lumens are how you would have to measure it along with the surface area. It is confusing so people just say you need this many watts per gallon.
You probably could have put this thread in the tanks section and you probably would get more replies, I don't know if a mod could move it?
15 Gallon NPT
1g no tech bowl in the making
Last edited by kfryman; 06-22-2012 at 11:48 AM.