With the Aquascape UltraKlean Biological Pressure Fish Filter， you can say bye-bye to gross green water. These pressure filters feature high-output UV clarifiers to help get rid of green water. They’re packed with BioBalls for both biological and mechanical filtration. They also have a low-maintenance spongeless design， so they’re super easy to use. The cleaning mode backwashes the filter in minutes， and you never even have to open the canister. The filter even features a programmable bulb-saver timer that helps to make your UV bulb last.