pond algae question

Asked February 22, 2017, 7:59 PM EST

We just purchased a property with a 3/4 acre pond that averages approximately averages approximately 7 feet deep. The previous owners stated that they have always treated the pond for algae but left us very vague instructions on how to do so. They did leave behind a coffee can full of copper sulfate and stated that they have tried other chemicals in the past but they felt this worked the best. The pond gets full sun through out the day with no shaded areas. They did state that they typically spread a certain type of straw over the ice during the winter months which eventually goes to work on the algae when the ice melts however, Ohio has already seen very warm weather here in late February and we are already seeing algae form on the surface. The pond does have bluegill, bass and catfish in it and my family will be swimming in the pond. What is the best form of treatment and when and how should we apply. Any info that can be shared with us would be much appreciated.

Stark County Ohio

3 Responses

You have to be careful when using copper sulfate as it can be toxic to fish in high doses. There are other chemicals on the market that are just as effective, without the risk of toxicity, especially considering if you don't know what concentration of copper sulfate the product in your coffee can is. Barley straw does work, but if you have an active algae bloom you can treat it with an algaecide there are many in the market or to keep algae and bacteria down you may want to consider using UV sterilization. You can't kill your fish with UV.

What is the timing, when do I want to treat whether I use the copper sulfate or choose anot her method?

Generally you want to treat before your algae bloom gets worse. So early spring is recommended. However it can depend on which product. Some products are more effective once the water warms up. For using copper sulfate timing doesn't really matter as much as alkalinity. See the publication below for more info on using copper sulfate. http://edis.ifas.ufl.edu/m/#publication?id=FA008