The general rule of thumb for coral is 4-6 watts per gallon, and soft corals will live and often thrive under normal output flourescents at a little less if they are within 10 or so inches of the light source. I do not have experience with anenomes but their light requirements are higher and the intensity must also b higher like halides, though don't quote me on that one. I have noticed the stupid aiptasia anenome seems to do just fine under 4 watts per gallon in my reef. It won't take long before the electric meter will be spinning like crazy and you'll be saying "Hmmm, I wonder if I can wire one more bulb into this thing somehow"