i have literally hundreds (mid to high) of tiny snails -- about the size of a nerd (the candy). It's cool watching them grow up. Have some juniors -- about the size of a skittle -- now too. I can't be sure they are all the same species, but from the junior ones, they are nassarius.
Cleaner shrimp likes to eat them though. I had a TON of stomatella snails too, but shrimp seems to have wiped them out as I don't see them anymore