Q&A for How to Make a Siphon

To create a siphon for a fish tank without the risk of accidentally getting aquarium water in your mouth, start by holding the siphon hose with your left hand and pinching it about halfway down to block water flow. With your right hand, immerse the siphon head in the tank and fill it with water. Maintain the pinch in the hose and wait for the water to drain down into it. Rotate the siphon head 180 degrees underwater, pointing it downward. Release the pinch on the hose, allowing gravity to pull water through the siphon hose and initiate the siphon. Although it may require some practice initially, once you master the technique, it becomes a reliable method, eliminating the need for a manual pump to start the siphon.

Use a turkey blaster or a syringe on the end. Anything that can pull a slight vacuum on the end should start the flow of water. Make sure that there is a tight air seal around the end or you will not be able to pull a vacuum.

A siphon typically consists of flexible tubing made of materials like plastic, rubber, or silicone, along with connectors and end pieces to facilitate the flow of liquid. Additional accessories may include clamps, suction cups, or flow-control valves, depending on the application. These materials are chosen for their durability, flexibility, and compatibility with the liquids being transferred.

To create a simple vacuum siphon, position the source container higher than the destination container, and insert one end of a flexible tube into the liquid in the source container. Raise any part of the tube above the source liquid and keep it there. Then run the destination end of the tube down to the other container. Start the flow of liquid by briefly sucking on the tube until it is filled (or mostly filled) with liquid and quickly putting that end into the destination container, taking care not to let air enter through the destination end of the tube. Maintain the siphon by keeping the destination end of the tube lower than the source container. You can stop the siphon anytime by raising the destination end of the tube higher than the source container (or by simply removing the source end of the tube from the source liquid). (The higher the source liquid is above the destination container, the faster the siphon will work.)