The Clack WS-1 Clack WS1 control valve.

The best DIY softener control on the market. Period.

Variable Reserve and Soft Water Brine Refill.

Plus you can replace any or ALL its parts in 5-15 minutes.

All parts are o-ring sealed and come off with either a nut or a retainer clip/pin, including the meter turbine wheel. The turbine wheel comes out of the side of the outlet, so no more removing the control valve and resin tank from the by-pass valve and reaching up into the outlet with long nosed pliers to get the turbine wheel out! To my knowledge no other control valve has that feature.

Spec Sheet