Internal Parasites

[Aces11]

I've never willingly owned a snail but my gut feeling and a quick search both say no it's harmless to snail and other inverts.

Thanks HUKIT, you've been a lot of help. The box says 'harmful to crustaceans' but I wasn't sure if snails are crustaceans or not. I just got 2 nerites yesterday and I don't want to kill them off. I guess there was still medication in the water from when I treated the tank earlier this week, so if it was harmful I assume I would have noticed by now.