Lighting for frag tank

[Dave3112]

I set up my frag tank the other day and now I need to get some new bulbs for my cheapo aquatraders odyssea T5 fixture. I will only have chalices in there and it is a 40 breeder. Should I run all 4 bulbs or just 2 and what combination of color temperatures? I like the ATI bulbs but I am considering trying Giessemann powerchromes. Any suggestions are appreciated.

Thanks in advance!!

Dave