I failed to run a 5 gallon tank with 14W of light; absolutely nothing would grow. I have a fairly sucessful 10 gallon tank with 28W of light, complete with pearling plants and hygrophila that grows a centimeter every 2 days for a small stalk and a centimeter a day for the big established plants. Despite that I plan to rip out the hygrophila and replace it entirely with Rotala Indica; the smaller, more orderly leaves of the Rotala will look better in such a small tank. The Hygrophila is also needed to plant my 70 gallon once it is set up; the more plants I have at startup the better the project will go.