Re-create Heron's Fountain From Water Bottles

I originally made this project for a client's website. It's a fun experiment that led to a lot of discussions about perpetual motion and free energy. My version does not exhibit either of these properties, but you may be able to fool people into thinking it does.

This is a really easy build and would be a perfect project for to build with your kids. Maybe you could even sneak in a lesson on fluid dynamics or perpetual motion?

Step 1: What You Need: Supplies

Here is a lit of the items you need for the build. As you can see, it's not a lot. The total cost of build = $2 (you can scavenge the 3 water bottles)

(3) 16.9 FL OZ Water bottles
(1) 9" length of tubing
(1) 11" length of tubing
(1) 15" length of tubing
Small amount of clay

Note: The tubing is for aquariums and is 3/16" thin wall rigid tubing. Almost any tubing would work, even flexible, but the rigid makes it really easy. I was able to pick some up at a local pet supply store for about $0.50 per foot.

Step 2: What You Need: Tools and Equipment

Here is a list of the tools needed for this instructable. All you need are very basic hand tools, and that's about it!

Scissors
Drill (hand or electric powered)
5/32" drill bit (slightly smaller than the tubing diameter)

Step 3: Make the Fountains' Reservoir

Cut (1) of the bottles in half as pictured. Keep the bottom of the bottle, you can use it to fill the fountain when we are all done.

Step 4: Drilling the Holes

You are going to need (2) holes in each cap. Start by drilling the (2) holes in (1) cap, use a piece of scrap wood to support the cap.

When you are done with the first cap, use it as a guide to drill (2) holes into the top of the remaining (2) caps. You can place the caps top-to-top when drilling the holes. Now you should have (3) caps, each with (2) holes drilled in about the same location.

Step 5: Drilling the Holes Part 2

Take one of the caps and use it as a guide to drill (2) holes in the bottom of one of the remaining intact bottles. This will end up being bottle {b} as in the diagram below.

Step 6: Connect the Tubing

Connect the tubing as in the diagram below. All connections should be airtight. If you used the 5/32 drill bit they should be. If not, just add a small amount of modeling clay to seal the openings around the tubing. I had to seal the area between bottle {a} & {b}.

Note: Make sure the tubing is at the proper heights in each bottle. These heights are Very Important.

Step 7: Add Water and Enjoy!

Now all you have to do is fill bottle {b} with water and screw the whole system together. To start your fountain, add water to the upper bottle {a}. Enjoy your homemade Heron's Fountain. It will last a surprisingly long time....but unfortunately, not forever!