One of the mystery snails has been laying clutches the past couple of nights. I don't know which one (there are lots in that tank) and I don't know if they're fertile. Assuming they hatch, what's the best food to feed the hatchlings?
Keep in mind that each egg casing can hatch 100+ babies. I hatched three egg casing and got over 300 snails. They will over work your filter unless you have a huge tank. You can feed them plant wafers, different greens like spinach, and be sure to give them some calcium. You can use antacid tablets like Tums or human calcium supplements. If you do not want to hatch a whole egg casing you can cut a piece off with a sharp knife.