Irrigation question:

[just Warren]

For a backyard scale application:

I want to set up a dish that maintains a constant water level from being fed by a normal line.

There's a device that you can put on the end of the line and sits in the water and when the levels drops the device activates and allows water from the line to flow into the dish until the water level is back to normal.

I've totally spaced what this thing is called and am having a hard time searching for it.

Any help is appreciated.

[zxcvbob]

It's called a float valve.  Sometimes called a ballcock. (snicker)  Small ones are used in swamp coolers.

[Ben]

In the cattle water trough game, we call them float valves, and they look like this:

https://www.tractorsupply.com/tsc/product/little-giant-trough-o-matic-plastic-float-valve?cm_vc=-10005

They probably have smaller ones for your application.

EDIT: Bob beat me to the punch.

[just Warren]

Thank you!