a long time ago i had a puffer in my 20g, so i added a couple snails for him to eat. however i ended up returning the puffer. my 2 snails has turned into 20+ that I can count right now. They are pond snails, and i bought 3 assassin snails to help, but it is not making a significant enough of a difference. what could i add to my tank? *** heard loaches but wont they eventually be too large for a 20g? thanks.