You should give more information. What size tank do you have? How long has it been set up? How many fish do you have in it? What type of fish do you have? How often do you feed them? What type of food do you feed them? How much food do you feed them? Basically, small fish with small meals in a LARGE tank should not require frequent water changes or tank cleanings. If you have a smaller tank with a lot of fish that get fed a lot of food, then you are going to have to clean A LOT and OFTEN! The average recommendations are usually a gravel siphoning and a new filter for the pump about once a month. But this way you have drastic fluctuations between clean tank and nasty tank, sort of like the hills on a roller coaster. If you do a partial water change once a week or once every two weeks then the water conditions do not fluctuate as drastically, like a train car running over flat land. Get the idea? You will always benefit by feeding small amounts to your fish. Too much food will be wasted in the tank to rot and make for a nasty tank and many problems. Consider that fish in the wild may not get to eat every day, so a small amount of food goes a long way when your fish are kept in a tank. Happy Fish keeping!
