I tried 10k and 50k ohm pots from radio shack, all about the same. They were liner-taper potentiometers, I'm not sure if they are the right type or not. Only other type they had said audio potentiometer. Luckily for me I like the light almost all the way up. The corals seem to be opening up larger then ever with the new lights. Been about a week now and I'm seeing colors I didnt know I had.
thats good - i had to turn mine way down so i dont cook corals lol