How often do I need to clean my fish tank?
I have a 5 gallon tank, with rocks and plants along with a 5 gallon filter. I have one Marble Mollie fish and another orange Mollie (not sure of the breed, but it is orange with a bit of black on the tail). Both of the fish are female, and the orange one I'm positive is pregnant. I own a vacuum to clean the water and some water conditioner. How often must do a water change?