I hope this is the right place to put this.

I found a snail in each of my two tanks. One is a sort of round-ish, a burnished brass color, and the other is black, sort of pointed, one of the sort I sometimes find near our outdoor water feature, I think.

First of all, there is any chance that either of these will grow to be large, interesting snails that would be nice to watch?

Secondly, what do I do with them? I took them out of the tanks and put them in a glass of water, but I suppose I need to get rid of them somehow. Should I squish them? Put them outside? I hate killing anything. (I even remove spiders and put them outside - my husband thinks I'm nuts.)

Thirdly, is there a chance that there might be more of them, or eggs or something, and is there a preventive measure I could take?

Snails are REALLY good for a tank. yes they will get bigger and there probably are more of them. I've got some pretty big "pest" snails I'll take some pics and you can tell me if your's look like this.

These are some of the bigger snails in one of my tanks and I love 'em! They help keep every thing clean and tidy. They eat waste food and the algae off the glass and plant leaves. They also eat the dying plant leaves so that they're not rotting up the water quality. They're terribly useful little critters! I'd put some in my goldie tanks but the GF would eat them.

I find them to be extraordinarily annoying - true pests. They lay clutches of eggs all over everything and clog up the filters with baby snails. Mine do not eat algae much - and I want all the algae for the fish anyway. There is no "waste" I need for them to eat - I run clean, barebottom tanks.

I, unfortunately, seemed to have contracted a strain of "Snails from the Planet Krypton" - they cannot be killed. They are immortal.

Salt - even 0.3% that goldfish tolerate well - is said to kill snails. (not mine)

Prazi supposedly kills pest snail - (not mine)

"Had A Snail" pestacide supposedly kills snails. I cannot bring myself to use such a nasty chemical in the tank.

Squishing them works well.

I pick them out of the hard media. I wash them away down the drain from the floss. I squish the teeny tiny ones that are up on the edge of the glass. Anything that makes it into the actual tank's water is EATEN within moments by my voracious goldfish. They chomp them up and spit out the shells.

I have a few hundred teeny tiny ones that continue to grow in my cannisters and filters. I keep the numbers down by picking them every cleaning. The fish keep the tanks clean.

Don't let them get started. You will NEVER be rid of them.