Ok 1st off if you are having problems keeping it from dieing then don't give it any nutrients. I would stat by getting alittle more light like you said. If it is still small then 1 CFL will be ok but keep it close to the plant. also make sure you have a light air flow over it. 2nd you don't need a ballast for CFLs. you only need one if you are running HIDs or tube floros. Just keep you waters PH at around 6.5-6.8 for soil and 6.0 for hydro. Keep it simple.