I have two kinds of snails in my tank now. I have no idea where they came from? Are they going to repopulate like crazy? I have Otos as my cleanup crew, what shall I do to get rid of these guys. I am not even sure where they came from.
Have you bought any new plants recently? That's how I got the snails in my tanks... they piggy-backed their way in there.
Definitely don't use any chemicals to get rid of the snails!
There's fish out there that eat snails... but you have to think about what you'd do after they eat the snails.... and if your tank is big enough for them, etc... so I wouldn't recommend this method.
There's ways to 'trap' them and get them out. I usually just take them out myself whenever I see them. A couple of snails don't bother me, since they help eat algae... but they do reproduce like crazy! If you overfeed your fish, they'll become a problem.
What I recommend, is taking them out as you see them. If you see any snail eggs, get rid of them (usally on glass, plants, ornaments, etc...). Don't overfeed your fish, and it won't be a problem either.
I hope this helps some. I'm sure others will chime in with better advice.