An apparatus (10) for creating a use solution of a concentrate diluted, with a dilution rate of not more than 1:130, into a diluent (12) flowing under pressure in a line (22). A normally-closed, user activatable valve (18) is operatively coupled in the line allowing the diluent to flow in the line upon user activation. A flow regulator (26) is operatively coupled in the line downstream of the valve (18), configured to maintain a constant flow rate for the diluent in the line. A constant flow rate pump (32) having an inlet and an outlet is operatively coupled to the valve (18). The inlet is adapted to be operatively fluidly coupled to the concentrate (28). The outlet is fluidly coupled to the line downstream of the flow regulator (26).