I recent read that if you let the Sawyer freeze that it destroys it. I can't attest to this however. I'm highly doubtful of ANY filter that claims more than a few thousand gallons. We bought a countertop filter guaranteed for hundreds of thousands of gallons and within two months the water tasted and smelled bad. We returned it and the next one did the same thing in less than 45 days, plus it had a greyish tint. And that was using tap water. Maybe the industrial and group models like the Katadyn, but I personally would keep extra filters and parts on hand. Just one .mans humble opinion