Select the correct chlorine feed chemical (cal-hypo, trichlor, or liquid) and avoid incompatible-chemical mixing hazards

Steps

1. Assess current CYA and calcium hardness levels before choosing a feed chemical: trichlor adds CYA with every dose, cal-hypo adds calcium, and liquid sodium hypochlorite adds neither.
2. Choose liquid chlorine where tight CYA control is needed (e.g., a pool already near its CYA ceiling), and avoid trichlor as the sole ongoing feed in that situation.
3. Choose cal-hypo cautiously in pools that already have high calcium hardness, since it will push hardness higher with each treatment.
4. Store and dispense each chlorine form with dedicated, clearly labeled scoops/containers, and never combine different chlorine products (or chlorine with acid) in the same container, feeder hopper, or floating dispenser.
5. Train staff/techs that concentrated pool chemicals are never to be pre-mixed for 'convenience' — each product goes into the pool separately, following label instructions.