So I have some hitchhikers, tiny pond snails. I don't mind them for nor and only had 4, so I figured it was fine and I'd see what happened. I even moved them from my old tank to the new tank. Yesterday I noticed a couple on the filter uptake and didn't think too much of it, but then today they were still there and the shells looked empty. When I did the water change I found that yes, the shells were now empty. Tonight I noticed another one on there! I immediately turned the filter off and tried to free him but it was too late. I know they are nuisances but I feel bad for them--what a sad way to die! What can I do to prevent this, especially if I go buy any snails?