Science Experiment help? Smelly water?

Well, I was doing my science fair along with my partner about seawater desalination and we planned on converting ocean water from the beach into drinkable fresh water. It worked; the water was crystal clear... oh so we thought. My friend wanted to get a bacteria tester just to double check and I was going over to her house to purchase the item online. However, I noticed when I kept the desalinated water in my fridge and took it out, it had this pungent smell. It smelt like sulfur along with beach (XD). Anyway, can anyone explain that? Any brilliant scientist out there that can explain our problem?