The CS400™ Backwash Controller, by Pentair, has simplified the backwash cycle of Stark™ and THS Series® filtration systems equipped with diaphragm-valve face piping kits. This semi-automatic programmable controller, with Acu-Trol® Intelligence, can backwash up to six (6) filters in sequence via the integral multi-port pressure distribution valve. A backwash can be initiated in three ways: true semi-automatic backwash at the single touch of a button, via an external signal from a master filter room controller such as the Acu-Trol AK600 or by a signal from an optional differential pressure switch for basic, automatic backwash functionality. Features include user-configurable settings, alarms, automatic calculated backwash cycle time and valve control to ensure pump and heater protection prior to the start of the backwash cycle. The enhanced efficiency and economy make the CS400 one the most eco-friendly commercial backwash controllers on the market.