Pond snails
 

Keep the snails, they wont harm plants or fish. They will keep algae
growth down and eat away at any weed attached to the liner etc


wrote:
Hello,

My last pond question! Our pond is full of snails. I think that snails
can reproduce on their own, which is why there are so many. Should I
live and let live or do I need to have a snail cull? Presumably they
will not leave the water and are not a threat to the rest of the
garden?

Thanks.