Thank you Luisgo.....I have read many places about retro ktis for t5's and that might be what I am wanting, dont really know, and the 20k bulbs really look like 14k, although Im glad they dont look too blue. I think what Im after is the affect of a PC (that I used to have before these halides), but at the same time the ripple of the halides. When I see a tank with daylight, actinic, and the pinkish bulbs, thats what I am wanting....but I also want the power of the halides and the shimmer....is there a such thing as all of that rolled into one? I have the halides, but want to do something similar to your setup, like adding the two longer bulbs to give it more color, maybe one actinic and one of those pinkish bulbs, but I dont know how to go about retrofitting it into my canopy. Wouldnt I just need to buy end caps and mount those then get bulbs the length I set the end caps apart? We have the same tank, I believe....72" long and shallow?