Kipass thanks for responding answers to most of your questions and by reading thru a lot of these scripts I already know I need to get a ro/di unit and a better protein skimmer. so the water answer is tap, the tank size is 55gal, feed fish every other day and enough that it is gone in a couple of minutes. the protein skimmer I have is attached to the filter that hangs on the back of the tank and is powered by andair pump