First Choice 4-Month Copper Algaecide 32 fl-oz

First Choice 4-Month Copper Algaecide is a long-lasting, copper-based pool treatment. It prevents and controls stubborn algae growth for up to four months, complementing standard chlorine sanitation.

Copper algaecide starts affecting algae within 24 to 48 hours, with visible clearing usually happening in 2 to 3 days. Dead algae turns brown or grey and falls to the bottom or gets caught in the filter, requiring full clean-up within 3 to 7 days.