I now have snails for the first time

[OBEYtheFISH]

Assassins prefer live food but will also consume algae wafers and anything else that lands on the bottom of the tank. They will also consume eggs, I've seen mine climb the walls of the tank specifically to go after cory eggs.

I started off with 7 in my 16 gallon a few years ago and now, I probably have 25 or so. They spawn slowly, not like most other snails. The young hide beneath the substrate for their first few months. There are so many people that want them that even if you ended up with too many, you could easily give them away.

For your situation, I would advise maybe 3-4 of them.

+1 on the live food
I have to look for pond snails in my other tanks just for my assassins!