Hi, I kept L. rotundafolia in a 30 gal. with a double lightstrip with regular aquarium bulbs with CO2 from 2 soda bottles injected into the Whisper 3 filter. I used small gravel called bitter walnut. My lights are on for 12 hours a day. My pH is around neutral. I grew the plant as a bunch/ stem plant planted in the gravel. It grew very well in these conditions. Ray