Algaecide
An algaecide is a chemical product that prevents algae growth or assists in killing established algae in pool water.
Definition
An algaecide is a chemical product that prevents algae growth or assists in killing established algae in pool water.
Typical Values: Follow product label; typically 1–4 fl oz per 10,000 gallons weekly as maintenance
In Plain Language
Pool algaecides are typically quaternary ammonium compounds (quats) or copper-based compounds. Quats are most common and act as a supplemental preventive treatment — they do not replace free chlorine as the primary algae control. Copper-based algaecides are effective but can cause blue-green staining in soft or aggressive water. Algaecides should be used as a weekly maintenance dose or after a shock treatment, not as an emergency treatment for an established bloom.
Why It Matters
Algaecide is a useful maintenance supplement but is frequently misused as an emergency green pool treatment, where it is ineffective.
Typical Values
Follow product label; typically 1–4 fl oz per 10,000 gallons weekly as maintenance
Last reviewed: 2026-06-01