If you have a snail problem, getting a snail eating fish is the worst ting you can do. Not only do these fish get big they will need to be re homed very quick. You will find snails are common if you over feed try find the root of the problem is my advise.
They were brought In on live plants. I dnt feed my fish lots of food. They eat all of it so I'd not over feed . Apparently assassin snails are very slow and only eat a snail a day. Maybe an option though or just live with them.
Assassin snails are only capable of eating 2-3 snails per week, if you want to fix a snail problem, reduce your feeding, a boom in snail population means there is a lot of decaying detritus in the tank, which generally comes from excess food.
Put a peice of weighted carrot or cucumber if im right leave it in overnight by morning will be covered in snails remove from tank remove snails and keep repeating process
You will always have snails in a freshwater tank with plants. I have yet to see a healthy planted tank that didn't have some. If you have too many, pull out or crush the extras. When you crush them they become high protein fish food. Cut back on feeding to avoid population explosions. You can never kill off all of the snails by starving them, that would starve your fish, but you can certainly limit their reproduction rates that way.