Sodium Hypochlorite
Sodium hypochlorite is liquid chlorine — a solution of sodium and hypochlorite ions used to sanitise and shock pool water.
Definition
Sodium hypochlorite is liquid chlorine — a solution of sodium and hypochlorite ions used to sanitise and shock pool water.
Typical Values: Concentration: 10–12.5% (pool grade); Shelf life: 60 days at room temperature
In Plain Language
Pool-grade sodium hypochlorite is typically sold at 10–12.5% concentration. It raises pH slightly with each addition and does not add CYA. It degrades over time, losing potency after 60 days of storage. Liquid chlorine is the preferred product for regular sanitisation when CYA is already at target range, and for shock treatment because it is non-stabilised.
Why It Matters
Liquid chlorine is the most common professional pool sanitiser. Understanding its degradation helps avoid dosing errors from old product.
Typical Values
Concentration: 10–12.5% (pool grade); Shelf life: 60 days at room temperature
Last reviewed: 2026-06-01