IN 12 years I have never had a snail problem in my pond. Did you introduce them Howee? and do you have fish? Yes they will eat your plants but wont do much else. Can you say a bit more about them etc?

No they introduced themselves. There are some smaller Ramshorn snails which i did put in, but loads of another kind which i'm assuming are one of the native species. We dont have fish so the snails are the top of the foodchain i think, and theyre multiplying at a fast rate.

As you dont have fish I would suggest emptying the pond to get rid of them is the only way. Also I think the plants have to go too as that is possibly how they were brought in to start with? Scrub the liner before refilling remember anything you put back in may reintroduce them?