You can either use a float switch or a float valve to fill your tank. Which ever one will fit your situation best.
Square D HG Float Switch
These switches are installed in the tank into a 2-½ fitting and are used to turn on and off your well pump or your fire bell. This is an electric switch.
Mechanical Float Valve
These valves go into the top of the tank and are used to fill it. The water reaches the float and when it reaches a certain level the water will stop flowing in. We stock 1 inch and 2 inch ones.
The CLA valve works like a float valve but keeps your well pump from cycling as often. It features a float inside your tank that will travel up and down 1 to 36 inches or more.
This is the only mechanical float valve that gives you a differential from on to off.