i just picked up 12g aquapod from a guy and he had a 150 MH hanging over it. one thought that i had was that the stock lights were right over the tank, and he had the MH light about 1.5FT above the tank. i really feel like there is actually more focused light in the tank now with the stock lighting.
i have the MH light but i'm not using it, and the tank is doing great w/o it, although all i have in there right now is some mushrooms and a seabae anemone