How to Get a Siphon Going

A siphon is a tube that carries liquid upward from one point to another. One familiar example of a siphon is a drinking straw. By sucking on the straw, you can bring liquid up from a glass even though liquid would normally only flow downhill. The trick to getting a siphon to work is creating low pressure at the far end of the tube, then letting gravity do the rest.

  • Place one end of your siphon tube in the liquid you are trying to move. Stick the other end in your mouth and get below the point where the liquid is.

  • Begin sucking, just like you would for a drinking straw. Do not take your mouth off the siphon as you draw the liquid up the tube, or the pressure in the tube will rise and the liquid will fall back down.

  • Suck until the liquid reaches your end of the tube. If you are using a clear tube, you will be able to see the liquid approaching. If you are not using a clear tube, you can wait until the liquid touches your mouth or you can suck until you think the liquid has almost reached you and wait for the liquid to come the rest of the way on its own.

  • Remove the tube from your mouth and curve it downward into the receiving container. Gravity will cause the liquid to continue flowing down your siphon as long as you keep the tube below the point from which the liquid is coming.