Undergravel filters perform best when water flow through the gravel bed is consistent and predictable, creating surface agitation for tank oxygenation. Air pumps and airstones can deteriorate or clog. As a result, they become noisy and ineffective...frequently requiring replacement and/or service. However, the Penguin 660 Power Head delivers constant flow with fully adjustable aeration and increased surface agitation...and it remains silent at all times. The custom air valve regulates air flow, the air filter eliminates noise and dust, and the intake strainer keeps debris from fouling the impeller...that's efficiency. Absolutely safe in both fresh and saltwater aquariums. 170 GPH Water Pump. U/L & CSA listed for dependability. Epoxy-sealed, moisture-proof motor and electrical components ensure safe operation. Adjusts to any demand. Bracket and suction cups expand mounting options. Shipping-Weight: 2 lbs |