I have some snails that apparently hitch-hiked into my tank, there's about 10 of them at this point. I'm not sure what to do about them, I'd rather not kill them as I don't like hurting animals. I can't tell if they're damaging my plants or anything...here's a couple pictures.
Normally they only eat plants that are on the way out anyway (or leafs that are). I see no problem with them. I have an influx of them in my 40g and I always just grab a few and drop them into my 10g so my puffer can eat them.
It's simply a matter of personal opinion, some folks love 'em, some folks hate 'em. They're usually harmless to plants, most species only eat dead leaves. They will help clean up leftover food, and will mainly reproduce according to how much of that is available. If you don't overfeed, they won't run amok.
They obviously came in on the live plants. They will over run the tank if you let the situation get out of control since they will breed like crazy. A few of them are fine to keep the tank clean but really you will need to get rid of most of them sooner then later so they do not cause a problem in your tank.
that there are lots of snails. I squish the excess and fish enjoy the treat. Typically if you gravel vac frequently, don't overfeed, and your plants are healthy the snails do not reproduce to excess.
I have purse snails (like the ones pictured) ramshorn and MTS in my heavily planted tank. If I can see them and catch them during water changes, they are fish food and I also occasionally do the lettuce trick when the MTS seem to run amok as they are the hardest to catch.
Overall however I believe that snails are a net benefit as they rapidly indicate bad fishkeeping habits (overfeeding) eat the dead plant material (keep my vals pretty clean looking) eat some algae and provide some live food to the denizens (snail eggs and crushed). MTS also keeps the substrate from developing deadspots though does not provide egg meals.
I keep them in all my bare-bottom tanks intentionally for clean up. I also purposefully overfeed so they do multiply and use them as Loach / Catfish treats.
