Ah, the joys of buying a beautiful new plant only to have it destroyed by stowaway snails. lol Well, it's pretty hard for them to destroy large healthy plants, but keep an eye out so they don't chew them up too much! I ended up with a purpely/red Apple Snail, he's gotten rather big. Unfortunately many "Pond" snails came with him. My apple leaves the plants alone, but the pond snails go munching on them and they breed so fast! I started out with two as well, and in two months I had hundreds. And the little ones are hard to spot. My Kuhli's keep their numbers down a little bit, but they don't remedy them, and once you have them, it's near impossible to get rid of them if you decide later that they're an issue. I've tried all those home remedies, and even re-did my tank, but eggs obviously survived that!
They are lovely little cleaners if you don't mind holes in your plants here and there though, just keep an eye out for too many! When I was trying to catch all the ones I could see to get rid of them...I lost my nerve when I found a bunch of little pure white ones. >< Ah, when snails steal your heart, you must be insane. =p
I've had less issues with holes in my plants when I pull the snails off them when I see them and move them elsewhere. Sure, they come back, but it takes a while. xD Also, I like to bury a small piece of algae wafer for them, they all go for that and leave the plants alone. They also like the rinds on peas and green beans, and they're safe for your fish too. Well fed snails leave the plants -mostly- alone, so maybe that will help. I had ZERO luck with feeding/catching them with lettuce, and I left a good sized leaf in there for two days once before I got tired of it. lol
Ah, also, both my mollies and platies sometimes pick on the plants. Usually either females in labor, or pregnant and grumpy, or miffed males without an interesting girl to chase. They will usually slam into the leaves on a plant, and sometimes take a bite at the same time, though they usually spit it out. They only really do that when they're extra moody though, or as I said, labor pains. lol