Within the last 2 weeks I purchased 2 Black Mystery Snails for a 1.5 gallon tank. I've had experience with snails before and have had great success however all of a sudden my water went cloudy and the next day they were both dead. I'm not sure what happened but up until yesterday they were both very active and seemed to be enjoying life.

Does anyone have experience with snails? If so, any ideas on what could have happened to mines?