1.When you want to replenish or drain water out of your tank. Just place the nozzle in your tank. Press on or squeeze the operation bulb 5 to 7 times and the water will start to flow out of the nozzle. 2.Aquarium siphon can eliminate garbage in the sand without harming your fish It’s a soft system, so you don’t have to worry about tearing it. It’s simple and easy to use, and you can change the water without getting your hands wet. 3.Using our aquarium siphon can help you clean aquarium tank efficiently and quickly! Give fishes a clean living environment. 4.Wide range of products as substitution of fish for goldfish, betta and turtle, etc.