I use 6 T5 bulbs on my 24" deep tank with great results. I do think that BB's coloration is a bit more blue than mine though. I run all Geissman bulbs...2 aquablues (10K), 1 pure actinic, 1 midday (6.5K), and 2 Actinic plus (20K). I'm happy with the color it produces. I've got a FTS in the photography section if interested in checking it out.