Iman Mostafavi wrote
Tank is 26gallons, and I have a 15W fluorescent. It's probably
inadequate...

Correct, you need more light. I'm trying to remember the dimensions on a 26
gallon... is that 30" or 36" long? Either way, upgrading to a twin strip
standard fluorescent still wouldn't get you the light you need. A 55 watt
compact fluorescent would be fine for the plants you have now if you want a
fairly low maintenance tank. If the tank is 36" long, you might want to
consider a 96 watt compact fluorescent.

kush