Adding chemicals to ponds.

Asked March 16, 2020, 12:11 PM EDT

The last few years we have had chemicals put in our pond to control aquatic growth. I am concerned if this is a good practice or not. We certainly like the looks of the pond and the controls help for a good luck. But the questions are if this is good for the fish, or the environment or the general health of the pond. Some of the chemicals are Bio-Maxx, Aquathol Super K, Cutrine Plus, Cygnet Plus, Boizyme Adjuvant and probably others when required. The people who choose these items are from Mike Harris's company Mid-Michigan Ponds of Bath, MI. Mike has a degree in Fisheries and Wildlife as well as some of his workers. This pond is about 4 to 5 acres in size and was not an excavated pond. It is in a low area of a field that had drainage tile running through it. A low dam was built and the tile was broken so the water could not drain away. The sub soil is clay so the water does not drain away but since it was originally a field there is rich top soil on top of the clay making for very good aquatic week growth. The pond is about 7 feet deep. Seven years ago we had Mike repair the dams which were leaking and at the same time had two deeper holes put in that are 10+ feet deep as well as two aerators to help fish survive winters. We have not seen any fish die offs. Seven years ago we stocked the pond with 400 Bass, 300 Perch and 1100 Hybrid Bluegills all of which were around 4 to 6 inches long, purchased from Lagis Fish Farms of Gobles, MI. Three years later my grand son caught three 19 inch Bass so I think the pond provides a lot of food. Of course I know they are eating the Bluegills and Perch. So, we have a big pond, lots of fish, and lots of weeds and it is a thing of beauty as the house is on a hill overlooking the pond. I want to do what is best for the fish, the environment and for us. Are we doing the best or can we do better and in a more healthy way? It is not cheap either as I was quoted a yearly cost of approximately $5000 for monthly treatments for this year. John Schoepke, 13165 Center Rd., Bath, MI 48808 (about 15 miles from MSU campus) 517 641 4881,

Clinton County Michigan

1 Response


When you begin killing off aquatic plants, you also reduce habitat for fish, destabilize bottom sediments, decrease oxygen, and often increase turbidity. Unless you continue treatment something will grow back -- and it could be some other aquatic plant, perhaps an invasive species. I see that you are currently treating for both the larger rooted aquatic plants and algae, and perhaps emergent plants as well. If you're treating monthly, that's a lot of dead material piling up in the bottom waters, and a source of oxygen depletion. You're also reducing habitat for the fish. It's not that large of a pond, so you might consider a reduction in treatment. The fish are likely not going to be directly affected by the chemicals but the indirect effects that I've just mentioned may be very stressful to them.