I use mine for fry tanks. Lot easier to clean up snail poop than uneaten miniscule fry food, and fry poop. They go live with the adults when I'm using the fry tanks to breed. Just popped three of my snails back into fry tanks, and they're still a little nervy, but they've figured out that the fry can't hurt them and aren't anywhere near as annoying or scary as the adults.
Three of my other snails are still in a female Betta tank with 6 female Bettas, two Croaking Gouramis, and three African Dwarf Frogs, and they move around the tank, for the most part, like the fish aren't even there...they just keep their feelers to themselves.