I know It's never a good idea to buy a fish to do your dirty work but maybe if your were to use the advice above and purchase a singular Assassin snail you may have some luck. It will feed off of the other snails, will not damage your plants, will take up a very small bioload, and (someone correct me if I am wrong) do not reproduce asexually. So, after the problem did get under control you could keep the little guy to fend off any further infestations without the worry of suddenly having too many assassin snails.
Of course, eradicating the population with the potato as suggested above and picking them off the glass will help speed up the process as well.
Of course, eradicating the population with the potato as suggested above and picking them off the glass will help speed up the process as well.
