My green apple snail died yesterday very randomly (i dont know why, he was new) and my yellow one didnt seem to notice. Then this morning i though it had died too! But it didnt, its fine now, i quarantined it and it took over half an hour but it finally came out of shell whole way (it was hanging partway out like it was dead before) and is now happily climbing around the quarantine tank with the nerites. My water had dropped down from 82F (its been hot, so i unplugged heater in like, july and temp never went down) whole way to 75F overnite and i plugged heater back in this morning. Could the yellow snails problem have been the cold? The "quarantine" is not my quarantine tank, its just a little plastic fish bowl i threw snails in to keep an eye on them for a few days where i wont have to search for them. The nerites havent had any problems at all, and are full of their normal energy. Water in bowl is same water in tank with no additives or anything that arent already in tank water. The only stuff i have been putting in my tank water past two weeks is a Tetra safe plus water conditioner that has Nitraban nitrate reducing granules in the mix. It doesnt say anywhere not to use with snails, and it doesnt hurt the nerites. That couldnt be hurting my apples could it? Theres plenty of algae growth on the fake plants and back wall of tank, so they're not starving, and i feed them algae wafers (well, i feed my pleco algae wafers and they share it, aka steal it from him) so they definitely have food. Any ideas to what is hurtung my apples and how to fix it? Remember its just the apple snail(-s if you count dead one) that are affected, no fish or shrimp or other snails are having problems at all.