Controls most species of algae with very low concentrations of copper sulfate. Copper Sulfate treatment is more effective when used in water that is 60°or above. Works by direct contact with algae. ITEM NO: 22613936 DESCRIPTION: Crystal Blue Copper Sulfate 5# Pail MODEL: 00333 UPC: 768980-003335 VL: A UM: EA PK: 8