Robelle 2112 Clear Water Combo Pack for Swimming Pools Includes one quart 3-Month Algaecide and one quart 4-in-1 Water Treatment 3-Month Algaecide kills and prevents blue-green algae, yellow algae, and black algae 3-Month Algaecide is non-foaming and lasts 90 days 4-in-1 Water Treatment clarifies water 4-in-1 Water Treatment prevents oil and scum deposits