Keep A Spare on Hand
I believe 200 gallon cartridge life is a bit of a stretch, but it's close. You can extend the life by routine brushing until the inner matrix is exposed by being worn away, then replace. Routine brushing also increases flow rate. It's not necessary to carry a replacement unless the water quality dictates it or you're traveling to a 3rd world country & be gone for awhile, but keep an extra @ home just to be safe.