Or you could put a shop light over the tank, thinking about doing that with our 50g, since I hope to end up planting it. 4' shop lights give out and average of 80w if they have 2 bulbs. Plus my 20g tank has less than 1wpg and my sword plant is thriving(could be the flourish tabs). But since I just got another sword and an anachris I'm looking into a compact fluoresent fixture that would give me 2.75wpg.