Pond Boss Forums INTRO New Forum Member Introduction Query from England

Hi I'm a real newbie from UK. We have a small lake around 500ft long by 150ft wide and 7ft deep. It is getting covered by weed in a thick mat (it looks like a form of Elodea) and it is hard work hoiking it out into a boat and throwing it to rot on the shore. I'm told that in the US you use grass carp to cure this problem. However, I find that we can't buy them easily here in the UK because of worries about releasing them inadvertently into the wild. There are sterile ones which we could get with some difficulty. Is this worth it, guys? Would they cure the problem? Any thoughts very much appreciated.

Greetings, Weedy.
If the plant is Elodea, it's one of grass carp's favorite diets. Soft, fleshy stems and leaves, easy to digest, etc.
I've used grass carp for many, many years and they can be an excellent tool in the lake manager's tool kit.
They are "Green", and stocked in the right numbers, quite efficient. They don't work fast, if stocked in the "right" numbers. You'll get conflicting reports about how many to stock.
They could be an excellent choice in your application. In order to protect wild waters, it's wise to build a fence to keep them from escaping, as they do like to go with the flow downstream.
If I were in your shoes, I'd find someone in England who has used them and see the results and find out what they did in order to stock them.
To directly answer your question, Yes, they CAN reduce the elodea. The number you choose will determine how long it takes. Determine the number by calculating the percentage of coverage of the lake. In my opinion, to gain control of dense elodea, you'll need to start with 4, maybe 5, per vegetated acre. One other piece of advice...make sure the grass carp are at least 10-12 inches long.

Weedy -- what fish species do you manage in your pond? This is general curiosity rather than something related to your grass carp question.

If your lake is smaller then it's possible to clean it using a heavy chain and two tractors. Connect each end of that chain to a tractor (they are on opposite banks of the lake/pond) and pull it. Chain goes down to bottom and it pulls out any elodea type weeds. Do it again for a few times and you will see a nice result.
In cases with small ponds it's possible even with lighter chain and 2 strong men.
But it seems like it's not the right case

Of course, this isn't a real solution because it solves the problem temporarily. Grass carp would provide much better service if only they eat your weeds (can you provide any photos with it?). There were some that my grass carp didn't like so I had to do some work with chain

I'm certainly not one of the experts but I do not recommend that you try to control Elodea through manual removal. Elodea spreads through fragmentation, so if during the manual removal process you leave any fragments in the water it will spread the Elodea.

Before knowing any better, I tried manually removing Elodea and it was a huge mistake in my pond.

Read this thread regarding Elodea before you try to manually remove it...

Elodea overgrowth in trout pond