Ok ave a 20 gallon fresh water tank, it is planted  and the substait it flormax at the base, with small stones covering it.my problem is lighting!!! i have a standerd light in my fixture the way i bought it and it didnt seem to help my plants grow but when i moved my tank next to a window and the plants got direct sun light, the plants grow very well, now the problem is  when my tank is getting that natural sun light i have huge black bead alge bloooms that cover everything, i tried fixing tis problem buy getting two chiniese alge eaters and using doesages of alge remover,but its still bad and  i have givin up all hope on the natural sunlight, so next best thing a good light bulb, the bulbs at the pet store are very costly i was wondering if i could get the same thing at a hardwear store usch as Home dept or Lows? plz help