Frog Algae Blocker 4ProFROG Algae Blocker 4Pro is a professional grade algae prevention solution designed to protect swimming pools from green, yellow, and black algae while helping maintain clear, balanced water. Engineered for long lasting performance, it works continuously to inhibit algae growth and support overall water quality. Formulated to integrate seamlessly with existing pool sanitation systems, FROG Algae Blocker 4Pro is compatible with chlorine, bromine,