Knowing that lime softening and ion exchange remove hardness is only the starting point. A Class C operator has to actually run these processes — dosing lime correctly, recognizing when a resin bed is about to let hardness slip through, and executing a regeneration cycle in the right order. This guide moves from the fundamentals into the process control skills you'll be tested on and rely on in the field.
Recap: Carbonate vs. Non-Carbonate Hardness
Before you can calculate a lime dose, you need to know which "kind" of hardness you're removing. Carbonate hardness (also called temporary hardness) is the portion of total hardness that is chemically associated with bicarbonate and carbonate alkalinity in the water — it can be removed by lime alone. Non-carbonate hardness (permanent hardness) is any hardness in excess of the alkalinity, typically associated with sulfate, chloride