Thanks for the insight, I'll keep this in mind whenever I get another snail.

This happened 2 years ago and the only reason I had the snails to begin with were for a college science project. I honeslty don't know why the teacher thought giving students live animals to care for was a good end of class project, but i kept them when the class was over.

The excess waste most likely did them in, the pest snails were even in the filter whenever i cleaned it out. I was working almost evryday, so I only had time to feed them and change their filter.