I have what I believe to be the same problem on my 10 gallon. Except, I would be satisfied with 3.8 wpg. I happen to currently have almost double that right now with a 2x36 watt kit from AHS. Everything is great!! However, my het. zosterafolia is growing to about 2.5" and stopping. My rotalla wallachii is also stunted. I know that many people don't follow the usual 2-4wpg rules on smaller tanks but, I may have gone overboard. Is there any way to run both bulbs on the same ballast with separate power cords and at separate times. This would allow me to have them on at the same time for limited "peak" lighting periods. Thanks.