I have no idea where they came from but we have loads. What am I to do?
Naturally, I turned to the web. Loads of hits – nice to know I am not alone.
Summary is that they are pretty harmless, help keep algae down and are rarely a vector for disease. However, they do breed quickly and can potentially overwhelm a tank. I do need to get rid of them.
I say summary: of course there were strongly opposed views – some people warned of parasites that live on snails, destruction of plants, overloading the tank. They also indicated that getting rid of them is practically impossible.
There are fish that will eat them (e.g. clown loaches) BUT they are not the easiest of fish to keep, do tend to get large, and should be in a school rather than alone so a large tank is required.
There are chemicals that will kill them BUT that changes the water chemistry and leaves you with decaying snail flesh in the tank.
Most people advise keeping the population down by removing them by hand. Yuk! How you then dispose of them depends on how bothered you are about being humane to snails. I shall leave you to think about that.
I am overdue in giving the tank a good clean (25% water change, clean all the filters, clean the glass – and remove some snails) but suffering with a cold and asthma at the moment so will have to leave it a little while. Need to do it soon though,