So there's something wrong with my planted five gallon tank environment and I don't know what it is. I used to have nerite snails, and eventually they all died. I started with five. Two died, then about six months later the other three died. I had them for about two years so I figured maybe it was old age. It crossed my mind that it could have been the tank, but I didn't know what it could be so I didn't worry about it too much. I have a planted tank with one fish, and I waited a few months, and the algae started getting out of control so I decided to get more snails. I did a 50% water change (using Prime) and then went to the pet store and bought five more nerite snails. The temp range is good (76 degrees), the ph is testing at 6.0, and the ammonia and nirate are testing at 0. I'm thinking about doing another water change to see if that helps, but I'm worried it would do more harm than good. Does anyone have any suggestions? They're all curled up on their backs playing dead. They've been like that for a day and a half. I took one out and poked at him and he perked up, and then immediately curled back up when I put him in the tank again. I've never had any problems with snails before so I don't know what it could be. Is it maybe the ph? What could I do about that? They were all so happy and perky at the pet store. I feel like a snail murder. edit: when I test my tap water's ph, it's 7.6. second edit: I did a 20% water change and it brought the ph up to 6.4, and my snails aren't moving around, but they started to come out of their shells a little. So, I think all signs point to a ph problem. But I don't know how after doing a 50% water change three days ago the ph could have been at 6 if my tap water is 7.6. The Prime website says Prime doesn't effect ph and when I tested the water with prime in it before adding it to my tank it was at 7.6.