Actually, my wisteria has become a floating plant. I put it in before I bought fish, and the low light/low nutrient situation I had before buying a better bulb caused it to start dieing off. It was my first attempt at a planted aquarium, so I decided to let it go until dead before removing it. After the stem rotted through and it started to float, I put in the new light and it boomed like crazy. Every two weeks I have to cut large chunks of it off and give away so my fish can continue to swim around. I could take it out, but I'm reluctant to do so. Sometimes one of my kuhlis disappears into it, and as he's rather small, you sometimes can't find him in there. I don't want to risk dipping him along with the plant.
The thing is, I don't mind the snails. I just don't want them to consume the entire plant. If they just nip a little and move on, then no big deal. However, everything I read about them says they eat plants like crazy. After 1.5 years of healthy plants with no apparent problems, a few weeks after the snails start to breed (I bought two banana plants that they "came with") I start to see leaves developing lots of little holes, but only where there are snails around.
I won't put chemicals in the tank to kill them off, because that's just wrong. My tank it too small for a snail eater, and putting in extra food to attract them for removal doesn't work as they ignore the food I put in. Sorry if I sound frustrated, I was just curious about how much they eat, but now I'm on the defensive, it seems.