Hiya, How many have you got? and how big are they? Apple snails have separate sexes so you will need a male and a female to get fertile eggs the females are often bigger than the males and are usually mature enough to mate by the time they are around an inch or so in size, if you see a pair constantly piggy backing then this is likely your pair with the male on the top, there needs to be a gap above the water line of a couple of inches for her to come out of the water and lay her eggs, they look like a small bunch of pink grapes lol
should hatch within 2-3 weeks depending on temperature, the tank should have a lid to prevent the eggs drying out or you will need to spray them daily, after the young hatch they are tiny so you may not see them for a bit, they will go into the tank in search of food, they especially like algae at this early stage but algae wafers and powder should do if your tank is very clean, they also like courgette slices.
