Many pond management companies (including most of our competitors) use Copper Sulphate and alum treatments to “fix” algae problems in a pond. This practice puts your pond on a fast track to disaster and may be hazardous to your health. Copper Sulphate is very detrimental to a ponds ecosystem. Copper Sulphate in the doses required to kill algae is 100x too strong for the microscopic organisms that form the base of the food chain. The label for Copper Sulphate directly states that it is lethal to aquatic invertebrates such as tadpoles, crayfish, and fish fry. Copper Sulphate is very ineffective in hard water, in very hard waters, Copper Sulfate can have less than a minute of active killing time on algae. This leads to higher doses of copper to increase effectiveness which in turn leads to more copper accumulation in the pond sediment. Also, the sulphates bind the iron in the water. Iron is necessary for phosphorus removal . Phosphorus is one of algae's primary fuels for growth. Continued Copper Sulphate usage leads to faster and more excessive algal re-growth. In our opinion using Copper Sulphate to control algae is “pond mismanagement”.