I use 75% actinic and 25% 10k in my lighting setup and in my opinion I have great color and growth. I have a 6 bulb set up. However I am sure that when its time to buy new bulbs I will probably go with grimreefers bulb suggestions. Im still setting up my 29tall that will have 4x24w t5 with 50/50. Here is what grimreefer suggests http://tfivetesting.googlepages.com/combinatio