BioGuard Arctic Blue Algae Protector (Treats 24,000 gallons)

Winter Algicide is economical, non-staining and non-corrosive. It helps protect water from algae during the off season months.Quaternary Ammonium-compound Prevents algae growth during winter months Non-staining pool algicide No mixing or pre-dissolving needed Formulated for use in chlorinated or brominated swimming pools of all surfaces and filter types