Here is my design for small flock waterer:
We only have 3 chickens and didnt want to get a large watering unit and they were still using the baby chick waterer and they were drinking that up in a day. So we reused the bottom from the baby chick waterer which has a 2 inch opening. You can pick up the bottom piece for about a $1.00 at most feed stores. I find this easier to keep clean and easy to clean with the smaller bottom. It's not really tippy either and as you can see I just used a few small bungees to hold in place just in case.
1- baby chick waterer bottom $1.00
1- bathtub gasket 2 inch $1.80
1- 4in Charlotte pipe 2ft $12.00 (you can make bigger or smaller up to you)
1- 4in Pipe end cap $2.50
1-Pipe reducer 4in to 2in $4.80
1-Pvc glue -non-toxic $6.50
Most of these items we got at Home Depot and the tub gasket was from Ace Hardware. I wanted this to fit in the girls pen and not take up alot of room. Not the cheapest design but some folks might have some of these items lying around and not have to purchase some of the items on the list. I also wanted to make this small to fit over cinder block with light bulb for winter so the water dont freeze. I have not tested this to see if it actually works yet.
This is just the basic 4 inch PVC pipe for water lines.
The pipe reducer 4 inches to 2 inches. Glue the reducer on one end and glue the pipe cap to the other end. Let it dry completely.
Take the bottom piece and stick your tub gasket inside to check fit. This will not work without the gasket as the pipe slides to the bottom and will not release the water it makes a suction. Take the tub gasket and cut one side if not enough of a gap clip some more gasket off. Check to see if it fits and that the cut end is aligned the with the small air hole opening in the bottom piece. The gasket is thick enough that the weight of the tube will not crush it down and it will still release water only when the level is lower than the air hole.
Just fill the pipe up with water, slide the bottom on with gasket aligned with air hole, and flip pipe over and check for leaks and that it is maintaining water at the air hole level. It's chicken ready!