Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants eat fish from copper treated pond?

every year I have fil. algea and I treat it with copper sulfate and it seams to do the trick...this year I stocked the pond for the first time.

from what I read, I should be fairly safe from killing fish since most fish kills occur due to lack of O2. Am i correct on this?

and would you eat fish from a pond treated with copper sulfate?

3/4 acre pond. owned pond three years. major duckweed/water meal problem with no fish population. dumped in floridone. added aerator with two air stations installed two years ago. stocked with BG,HBG,LMB,Catfish,Redear. all pretty small.


thanks
adam

Hey Adam,

I just bought some Cutraine but haven't used it yet. My concern is what it will do to my plankton bloom. I read some threads on this subject this morning. Bill Cody provided a pretty comprehensive reply in one of them and commented on copper sulphate. Answered a lot of my questions.

http://forums.pondboss.com/ubbthreads.ph...ite_id=1#import

Post is pretty old so there may be more up to date info now

Too much copper can be toxic and can cause a fish kill. Also, when you kill algae, the decomposition process consumes dissolved oxygen which can cause fish kills. General rule of thumb is 20lbs of copper per acre. If pond is 100% covered in algae, only treat half of it at a time, leaving about a week in between treatments.

I bought the Cutrine to have on hand as a last resort. I hope it gathers dust on the shelf and never gets used. My hope is I can address the FA this summer thru erosion control measures and introduction of "good" vegetation to use the excess nutrients. While waiting for that to take effect (maybe next summer), I will try to fight it by removing any floating I see.

I do not have an answer to the question as to whether the Cu causes issues with the safety of the fish fillets.

Bill that's what tilapias are for. Heard mudbugs will eat a lot of salad

Tilapia are illegal in Illinois cause apparently they wear little snow suits and live thru the winter here.

I want to add crawfish but I am light on predators in the pond so I want them focusing on BG spawn, not crawfish. Hope to have them once I get things balanced a little better. Also want to get the vegetation established before bringing in those two clawed lawn mowers!

Cu is supposedly not bioaccumlative, although it is on at least 3 government agency lists as a hazardous chemical. when bound it does not decompose and is a stable compound that eventually deposits in the sediments. In the sediments it can redissolve under certain sediment conditions or chemistries.

Different species of fish have different sensitivities to copper ions in the water. With trout, grass carp, and minnows being most sensitive, LMB are pretty tolerant and most other species somewhere in between. Most fish fry are pretty sensitive to applications of Cu strong enough to kill algae, usually 1ppm. Traditional application methods for CuSO4 results in uneven concentrations of Cu as it is distributed. Cu ions quickly become chemically bound or absorbed and inactive in most all hard water applications (total hardness >100mg/L, ppm) and slower to be bound and inactive in soft water low alkalinity situations..

Application of 20 lbs of CuSO4 per acft is 7.4 times the recommended application rate of 1ppm. Often FA is just around the pond perimeter thus treating that depth zone is the most responsible application method. When treating FA in a pond, generally the entire water column usually does not need to be dosed at 1ppm. Actually copper sulfate applied to a pond surface often does not penetrate the water column deeper than 2 - 4 ft due to the chemical binding forces of the positive charged copper ions in the water column. Copper is a contact killer thus direct application of copper solution on the offending algae is often the best treatment plan.

Good info, I should clarify my previous comment, in regards to fish kills, my understanding is that 20lbs/acft is maximum label rate and should never be exceeded.

I would love to go the barley straw route (as mentioned in another post ) I used to use this method in a small garden pond that I had. But am I correct in saying that it works for planktonic algae and not filamentous algae?

Adam

It all works to a certain extent. But, it does take some planning.

One of my most successful FA-infected pond clean-ups involved several ponds on a farm, where little had worked before. It was on a farm with lots of manure, at the bottom of a valley that also included a lot of manure polluted inflow from farms far above these ponds.

The multiple-generation family of this farm used a number of techniques to to control algae and weeds, included dies, various names of CuSO4, and other chemicals.

My approach included some pond dye -- but not in the ponds. I poured several lines of it on the ground above these ponds during dry times. I used it to find incoming paths of excess nutrients, which I felt were causing most of the issues.

It then included a bulldozer, a skid steer, and a small excavator.

Grading resolved nearly all of the issues.

By the time we diverted most of incoming nutrient issues, there were still a lot of excess nutrients in the ponds. We added 8-10 inch grass carp at 20 per acre. The grass carp were moderately successful during the first season. By the second season the ponds looked great, and the grass carp were now in excess of 20 inches.

I looked at the ponds about a week ago (third spring season). I now figure it is time to take out the grass carp, which have become monstrous.

The catfish we put in two and three years ago are doing fantastic. There are some incredible LMB. There are lots of really fat 8-10 inch BG.

During high-water times, there is a natural infiltration of green sunfish, creek chubs, and various darters. We built a special small pond for them that includes a lot of plants that uptake nutrients. The few fish that make it through that overflow provide snacks for the fish below.

We have not done any flesh testing for chemicals. Personally, I feel pretty safe serving the fish from these ponds at this point. A lot of water flows through these ponds that is now filtered by many crops from grasses and grains, to cattails, to waterborne flowers.

I've never had an FA problem and I controlled it in two different ways.

The first way was with a combo of 20 KOI carp & 6 Israeli Carp for one acre. With bass as predators I never had any more carp then the ones I put in. A slight down side was some turbidity.

The second way is with just a lot of plants and tadpoles that are great FA eaters. The only fish I have are minnows and will add some bluegill. The upside is very clear water. The downside is too many plants for most people.

Adam,
I have a friend with a 20 acre pond in SE Texas that used copper sulfate on his FA issue a few years back. He let's me fish his bow to control over-population of LMB. I have eaten the LMB before and since the application of copper sulfate without any issues. I'm not telling you that it's OK and safe to do. I'm just sharing with you that I've done it without any negative repercussions that I can speak of.
Charlie