T-5's will work fine for a water depth of about 22 inches max. if you have 5 to 7 watts per gal. its not really the watts per gal as it is the depth of the water and lighting par, you need to balance your lighting and determine at what depth you want to put things, the more light loving corals need to go high and the ones not needing so much light can go lower. There are some very good articles in our articles library at the top of the page click on articles and you can select the category you want, if you dont see it go to misc. if you have any difficulty in locating the articles, send me a pm and ill be glad to help you. some back ground reading surly couldnt hurt on on the issue of lighting. good luck, thanks for the question.