เครื่องคำนวณ Shock สระว่ายน้ำ ⚡

How to Use the Pool Shock Calculator

Enter your pool volume, current free chlorine (FC), and current CYA level. The calculator computes the SLAM (Shock Level Algae Management) target FC as CYA × 0.4 — the chlorine level needed to kill algae when stabilizer is present.

Choose your shock product: calcium hypochlorite (cal-hypo 65%, most common), dichlor (56%, adds CYA), or liquid chlorine (12.5% NaOCl). Each delivers chlorine differently and is dosed accordingly in oz, lbs, grams, or mL.

Always shock in the evening. Pre-dissolve granular shock in a bucket of water. Wait until FC drops to 1–4 ppm before swimming — typically 8–24 hours. Retest chlorine and CYA after the pool has fully circulated.