A tank that’s heaving with snails could indicate a lack of maintenance.
A tank that’s heaving with snails could indicate a lack of maintenance. Neale Monks gives his advice to a PFK reader who is struggling with snails.
NEALE MONKS RESPONDS:
There’s no simple answer to this. A lot depends on how desperate you are to eliminate the snails completely. If you want to get rid of them all, then essentially stripping the tank down, changing the gravel, picking snails off solid objects (including filter media), and very likely replacing all the plants will be part of the answer. Traps of various kinds are on sale as well, and these do work if used correctly. Even then, some will survive, so you’ll need to keep remove any remaining snails as and when you see them. It’s a lot of work, but this approach can succeed if you’re persistent. It’s a lot like weeding a garden: doable, but not something you do once and for all!
Don’t forget snails do little serious harm in fish tanks. They’re unsightly rather than dangerous. Indeed, Malayan livebearing snails do some good by aerating the substrate. It’s perhaps better to think of them as warning signs that your tank has too much organic detritus lying about. A clean tank is, very largely, a snail-free tank. Where you see a lot of snails you’re probably looking at a tank that could do with a tidy up and perhaps stricter maintenance when it comes to removing uneaten food, dead plants and so on.
4 ways to control your snail population
Disinfect your plants: Rinse all new aquarium plants and treat them with an aquarium snail treatment before introduction. 
Add a snail eater: Some fish will eat snails, such as Botia loaches and puffers, but they’re not suited to all tanks. Try a snail-eating snail in the form of Clea helena. 
Buy a snail trap from your aquarium shop, or make your own using a couple of slices of courgette which can be placed under a saucer in the evening. Remove the snails that collect on it a couple of hours afterwards and repeat. 
Minimise the food the pest snails can eat and turn into baby snails. Don’t overfeed your fish, remove dead/dying plant leaves, scrape away algae and syphon away organic detritus regularly.