Maintain optimum water quality by removing unwanted waste with Aquatopâs easy to use gravel vacuum. This essential tool includes a unique ball valve siphon to quickly and easily siphon water and detritus from your aquarium to your bucket or drain. The durable gravel head allows you to effortlessly sift your gravel substrate and also includes a gravel/fish guard to prevent the accidental siphoning of substrate or aquatic creatures from your tank. The AGV Series of gravel vacuums comes with a 6â ft hose giving you plenty of slack for taller tanks. Also included is an On/Off flow control valve allowing complete control over the water flow into your collection bucket, or add a hose extension onto the barbed fitting of the flow control valve to direct your waste water to an appropriate drain.