This may help
http://www.drsfostersmith.com/pic/ar...id=287&aid=228
All lights area sold by watts. And really depends on type of coral you will want. All softies will live in high PC ( power compact ) lighting. Where LPS and SPS require T-5 or MH ( metal hilide ). But my t-5 dont seem to support some LPS. Decide on your budget then your stock and this will help with your purchase.