HTH Ultimate Algae Guard 1 Qt. Liquid Algae Control

6-in-1 formula treats up to 90 days, kills and controls green, yellow, and other algae, good for all pool surfaces, non-foaming, concentrated all-purpose algaecide, and can swim immediately. Active ingredient: Copper Ethanolamine Complex 6.48% and 93.52% other ingredients. Compatible with salt systems.