Two reasons to shock: combined chlorine above ~0.5 ppm (chloramines — the chlorine-smell-and-burning-eyes culprit) or visible algae. The calculator does both. Enter your pool gallons and either your combined chlorine reading (for break-point chlorination, ~10× the CC level) or your algae severity (light / moderate / heavy, with type). Output is in pounds of 65% calcium hypochlorite shock. Free, no signup.
Don’t know your pool’s gallons? Rectangle ≈ length × width × avg-depth × 7.5; round ≈ π × radius² × avg-depth × 7.5; freeform is roughly 0.45 × length × width × avg-depth × 7.5.
R-0015 acid demand reagent drops
Enter your pool volume to see dosage recommendations.
