If you’ve maintained your cleaning schedule, your Caldera hot tub filters should last up to 3 years. You may want to replace them sooner if maintenance has been sporadic or your hot tub has seen heavier than normal use.
Replace your filters sooner if the filter is brown, gray or green, or if it stays dark yellow after cleaning. You should also replace filters if you notice that the pleated part becomes flat or the fiber begins to shred or fall apart. Also replace if the top or bottom of the canister has a split or crack.