I just picked up a 30 gallon cube tank and i'd like to stock it full of various live plants. for now i have an aqua glo 15 watt bulb. I figure they sell these tanks with the 19 watt ballast not anticipating anyone ever wanting to put plants in their aquarium. I plan on keeping mostly tropical fw fish, such as the gouramis and rasboras i have. The tank is 20" wide(the fixture on there now is 19", housing a 18" light), and the water is 20" deep. So, the hole is getting deeper, and i'd like to get the problem solved for under 50 bucks. any suggestions?