Heat is definitely an issue in my case. My growrack has two levels, each with 4 t12's, and it gets up into the low 80's when they are on.
So - any idea if I were to use 6 t8's per level vs. the 4 t12's what the heat output might be like? I'd like to keep the light level high, but lose some of the heat output. Would t8's allow this?