Hi Grim, let me say thank you first for this VERY informative thread, but after a couple of hours of reading, I am SO confused.lol I just bought a used 4 bulb t5 fixture with new bulds, 7 bulbs came with it because he was using it for actinics and he was playing with the colors. So what I have is Giesmann- 2 actinic+, 2-aquablue, ATI 1-aquablue special,1-blue plus, UV 1-super actinic. What would you recommend on the layout and order? I'm not opposed to getting other bulbs either like a fiji purple or something, I just want it to be "right". Thanks so much.