Sorry for the confusion, I was referring to over his sump, not over the tank itself. Basically what am I looking for to maintain growth in the sump?
OH for the fuge inside the sump ...correct?
Well hydroponic stores sell 6.5k bulbs for plants...and they are cheap...having some Mcgyvered lighting hanging over it with those bulbs is sufficient.
Its pretty much all you are shooting for is a grow light... I used them on a Hob fuge...worked well.