Copper Sulfate Pentahydrate can be used to destroy algae in water supplies. It controls tadpole shrimp in flooded rice fields and is used as a sewer treatment to destroy roots.

Fine Crystals Copper Sulfate can be used as an ingredient in Bordeaux Mixture sprays as a fungicide to control plant diseases. It is an ingredient in wood treating chemicals to protect against mildew and rotting. In industrial applications,Copper Sulfate finds use in production of chemicals, dyes and pigments, in the steel industry for pickling and plating and as a flotation reagent in recovery of zinc and lead in mining.Algae can be controlled with extremely low concentrations of Copper Sulphate (ensure you don't overdose as too much copper may kill any fish),also find useful in ceramics, copper plating, general lab reagent and even inhibits growth of bacteria such as E. Coli

Also to make copper crystals....