I have a 150 gallon tank and it is mostly zoas palys and rics. I have phoenix over the tank now, but sometimes feel that they are too strong. There is 150w at each end and a 250w in the middle, all running off of icecap ballasts. There is a lfs that I go too in Orlando and they have 20000k XM's on one of there tanks and my Phoenix bulbs are just so much brighter. What are your opinion's on the XM's?