"2wpg" doesn't specify a light intensity. You are using CFL bulbs. If those are mounted horizontally in a standard incandescent bulb socketed hood, you are getting relatively low light. If they are mounted vertically in dome shaped aluminum reflectors, you are probably getting high light. If the tank is a low one, like a 20 long tank, you very likely have high light. If the tank is a high tank, like a 20 high tank, you will have much lower light. The dosing needed depends on the light intensity.Thanks for the help, and yeah, they really do. I guess my next question would be what would be recommended for dosing? Lighting is at 2wpg with 13w 6500k CFLs.