yeah, bennerkla has the right idea, Over my 30 gallon I run 150 watts of HQI-Metal halide (20k) and also another 130 in actinic. (which if anyones counting thats about 9.5 wpg.) Seems like too much. It's not. It's all about heat.
On my 10 gallon I run 130 watt PC lights. 13 wpg, nothing bleaches because its PC, you can never have too much PC light if you can keep it cool. Whereas, when I had the 175 (single ended) XM Metal halide 10k most everything inside (even with the light a foot above the tank.) It raised the temperature of the tank within one hour 4 degrees. My advice is try it, get a personal fan from wal-mart or something, try to keep it cool if it overheats, rethink your setup.
(oh and by the way, I keep about 20 different types of corals in my 30 gal, and a few in my 10 gal. And i have mushrooms and zoo's also plenty of other softies...no problems.
good luck