Pond Boss Forums GENERAL QUESTIONS Water chemistry copper sulfate

First, let me say that I'm no expert on this subject. I will try to accurately reflect some information I have observed regarding my ponds health over the past several years. A while back, I took a course entitled "ecology for engineers." It was taught by a couple of guys that were leaders in their field, and very knowledgeable about aquatic habitat.

I have had some serious problems with the plants described above and in particular filamentatious algae. One summer, I had a major fish kill as the algae died during some cool August days. I've used cutrine and copper sulfate. They work. Given a couple of weeks, these treatments will knock it out. With a couple of treatments a year, no problem. You have a nice looking pond.

Here's the rub. I raise fish. I have bass, BG, cats, and crappie. The fish and particularly the BG and bass were not growing like I would like. The BG were stunted, and the bass were also very small. The cats did ok because I fed pellets. The water seemed like it was always cloudy.

During coffee breaks I would chat with the instructors to get their take on my pond and its health. Their come back was immediate and unanimous. I don't have an algae problem. I have a nutrient management problem. Killing the algae only releases the nutrients back to the pond to be used again. And, if I didn't cut off the source, the nutrients would only continue to accumulate. Also, once the copper precipitates out, the problem will come back likely worse than before. So, will I have to treat forever?

Their 2nd observation. The copper based algaecides kills the algae, and other zooplankton, invertebrates, etc. which are part of the food chain for BG, fatheads, shiners, and other critters. Also, the cloudy water (which could be nutrient based), detracts from site feeders like LMB. This could be the cause of both small BG (3") and bass (12").

The solution is beginning to unfold (for me at least). I'm dealing with a half acre pond so it is probably much more practicable to do what I'm doing for my situation than for others. Here are the steps I've implemented so far. No fertilizer for the lawn around the pond. On other areas on the property, I use a slow release fertilizer (not the cheep stuff) with low or no phosphates. Aerate. This helps break down organics naturally, and provides O2 for the fish. If the alga builds up around the edge, mechanically harvest it. This gets rid of the algae as well as nutrients (a couple of hours two or three week ends a year in my case). The final thing I've done is to use a bacteria / enzyme additive. This has been very helpful in removing muck from the bottom, and I've really noticed the water clearing up. Visibility has gone from 6" to about 4 feet.

This past year is my third year without Cu treatments. The water is clearer. The BG are now about 8" on average, and I've caught some LMB in the 20" range. The larger cats are about 30". I think if cats can find feed, they are very tolerant of water quality. I hope sharing some of my thoughts is helpful. If I'm off base on some of my observations, the experts on the forum can help with more scientific explanations.