Sean the tank has a front cover to match the stand, it blocks the light.
Domboski, how did you do it?
Jonathan, I had one 4' T-5 and one 4' Vho, but I wanted the entire length of the tank to get the actinic.
Plus the T-5 couldn't even come close in color and output dept.
I see VHO's along side 400's in a lot of fixtures, I guess it would all depend on ventilation and distance between them.
I'm sure someone here knows how much heat they can withstand.