I use 2x 48" Dual 40w flourescent fixtures (Total 4x 40w = 160w) over my Fuge. I started with 4x fist size clumps of Chaet, and in the past 4 months that has grown to about 3 Sq Ft. Enough that I am going to have to start removing it.
In my sump, I have a single Dual 40w flourescent fixture (Total 2x 40w = 80w). The water is a little deeper, but a fist size clump of chaet has just doubled in size over the same time period.
Eob A. :beer: