You’ve probably heard someone mention the “cycle” to you in regard to your aquarium. What “cycling” refers to is the good bacteria that needs to colonize your filter in order for the water to be perfect for your fish. The fish give off waste and the bacteria consume the waste. Once we have enough bacteria to handle the amount of waste we consider the aquarium “cycled”. We verify this by testing for Ammonia, Nitrite, and Nitrate. Once these levels are at zero we know the water is ready to start adding more fish.