# Fast and Easy Science Fair Projects: Siphon Fun

Updated on December 30, 2019
Click thumbnail to view full-size

## Water drains to own level

Purpose: Discover how a siphon works.

Overview: A hose or tube can be used to create a "siphon," a device that drains liquids. A siphon will drain liquid from a higher to a lower level, even if it first has to travel uphill! A hose placed with one end underwater in an above-ground swimming pool and the rest draped over the side and down to the ground will drain water out of the pool. To get the flow started, it may be necessary to suck on the low end of the hose. Once the flow begins, gravity pulls the liquid down, creating a vacuum in the tube that draws the liquid up and through the tube.

Hypothesis: Water can be made to rise above its level through the use of a siphon.

You need:

• 2 two-liter soda bottles
• Long piece of aquarium tubing
• Several books
• Water

Procedure: Stack books on a table. Fill a clear plastic bottle with water and place in on the books. Set and empty bottle near it, but on a lower level - not on the books

Insert one end of plastic tubing, available at pet shops, into the bottle of water. Be sure there is space around the tubing in the bottle's neck (if it is air-tight, the siphon will not work). The end of the tubing should touch the bottom of the bottle. Suck on the other end of the tubing, as you would a soda straw, to get the water flowing, the insert the tube into the empty bottle. Push the tubing in so it touches the bottom of the bottle.

Held Constant is gravity, the volume of water, the lack of air in the tube system, and the bottles. The motion of the water from higher to lower bottle is the Variable.

Results and Conclusion: Write down the results of your experiment. Come to a conclusion as to whether or not your hypothesis was correct.

Something more: 1. Once the lower bottle is filled, do you think that the siphon would work in reverse? What if the bottle was now raised higher than one of the books?

2. Does it take the same amount of time for the bottle to empty each time the experiment is done, so that it could be used as a sort of "water clock"?

9

11

17

working