hey a guy i know has tested many many bulbs (like Sanjia but tested 250w instead of 400w) and for best growth and overall benefit he finds the 10k Xm's work best...theres no disputing that this will give the best growth and is probaly the most natural......yea it gives out a little yellow but if suplemented actinics it looks fine......
spsaddict: although you get good color with 20k you just can't get the growth that you can get with 10k....and i have seen corals that are under 10k's with not to much actinic supplement(somthing like 2 110w bulbs) that show just as much color as corals under 20k XM's or Radiums
also almost all of the 12k or 14k's out there aren't made very well and don't give the color and growth you can get with ether the 10k or color with 20k.....you would think they are in the middle, good growth and color, but they just don't seem to give much of ether (have tried 12k and i see more growth and same color with my 10k)...................i am sticking to 10k intill XM comes out with a 12 or 14
Brad
heres the guys sight that tested all the bulbs....he's on another board as jb ny....i know he runs 10k 250w but i am not sure how much actinics (probally between 200w to 400w)
http://www.cnidarianreef.com