Hi JohnA!
In my tank i had 2 apple snails(one died recently, unknown causes) between the two snails i had about 40 baby snails (more or less)and some others that i think came from plants that i bought, anyways, about a week ago they all started dieing

(I have a snail graveyard in one of my caves LOL). I do know if your PH is too low the shells will get soft and the snails will die. so my question is, is there any other causes? My other apple snail hasen't moved in about a week..I'm not really fond of my snails i just want to know why this is happening.