Dialysis water purification system

A method for controlling a supply water pre-treatment system for providing de-chlorinated water to a primary purification system, said pre-treatment system comprising a supply water line in fluid communication with an injector, a static mixer and a plurality of filtration tanks, each of said tanks having a control valve for placing said tanks in normal or backwash cycles, each of said control valves having an actuation input for actuating said valve, and each of said control valves having a control valve position output, said method comprising:

• providing a controller having a microprocessor and concomitant data memory and having a plurality of outputs for supplying electrical operating signals and a plurality of inputs for accepting electrical signals of system parameters;
• providing an ORP/pH sensor in fluid communication with said supply water line disposed downstream of said static mixer for determining the ORP and pH of said supply water, said ORP/pH sensor having an output of ORP and pH;
• providing a flow sensor disposed in said supply water line upstream of said injector having an output operatively connected to an input of said controller representative of the water flow rate through said supply water line;
• and
• monitoring said plurality of filtration tanks when said control valves are in backwash cycles to determine the time period said control valves have been in backwash position;
• monitoring said supply water flow rate during said backwash cycle;
• providing an alarm indicative of inadequate backwash flow rate if said supply water flow rate is not greater than a pre-determined average;
• and
• providing an alarm of inadequate backwash duration if the time period said control valves are in backwash position is below a predetermined minimum.