I was changing the filter media in 1 of my HOB filters and I saw there are like 15-30 baby snails in there. I haven't had live plants in there in a few months so how long does it take for snails grow and can they hurt anything? I know if they go into the tank they will get eaten. Should I get rid of them or leave hem be???

I personally would remove them (or just chuck them in the tank- free food), however i dont suppose a small amount will do any harm. You will never end up with millions as your oscars will eat most of them.

You can get a treatment to get rid of snails. I have never used it so i cant say about how good they are or any pitfalls of the treatment