Sorry that I know nothing exactly about the Ramshorns. However, as for the common popular species in China, Cipangopaludina sinensis, it always have small babies in its tail tip. So, if you introduce any by accident into your tank, and you do not like them and killed them by breaking them, you may receive a booming of them in the tank.
I agree that the excrete wastes from the sanils are not so difficult to be catabolised than those from the fish, to some extent. However, if too many???
Anyway, I hope the Ramshorns are good kids in your tank. :lol: