I've never bred snails, but I've read up on it as I debated it. I would suggest using a sponge filter. Put it in one of your tanks and run it in there for about a month. Might want to occasionally squeeze some water from whatever filter media you are using in another tank on the sponge filter to seed it too. It might not be necessary but keep a heater in there to get some condensation on the sides to keep the eggs moist. Make sure you have a lid too. As for food just throw in an algae wafer in every once in a while or something like that.