Using Copper Sulfate in Ponds

The use of copper sulfate to manage algae was once a common practice and still continues to some degree today. Copper sulfate successfully killed algae and virtually any other plant in ponds. Although copper sulfate provided a successful short term solution for pond owners, the long term situation grew worse. Copper sulfate reacts quickly, limiting contact time to the day its applied.  

Copper settles to the bottom of the pond, where it remains in the muck as a heavy metal. The result of copper accumulation is long-term toxicity to aquatic life. This creates an imbalance the pond ecosystem.

A disruption in the pond ecosystem not only leads to many more algae blooms, it affects the growth of the fish population.

New copper compounds are as effective as copper sulfate, last longer, and are safer for aquatic life.  

What are the safe (and long-lasting) alternatives to copper sulfate?

A much safer alternative is a copper complex or chelated copper. Treatments like Cutrine Plus and Cutrine Plus Granular are examples of these. These treatments contain only 7-9% of elemental copper, versus 25% in copper sulfate.

These alternative treatments are safer because they release the copper ion more, making it less harmful to fish and other aquatic life. Chelated copper algaecides reduce the frequency of treatments because they are effective for up to 6 weeks after application.

With all chemical treatments, we recommend using only as needed. Chemicals may disrupt the natural balance in the pond. Algaecides kill good bacteria. Using pond dye after an algaecide treatment will help to limit the frequency of algae blooms.

Proactive treatment practices including pond dye, and beneficial bacteria will provide better long term results for your pond. Using these in conjunction with bottom aeration limit the amount of algae-causing nutrients in the water and muck. Over time this will yield better results than chemicals.