A Calder filter provides completely balanced filtration, which means the square footage of your filters has been carefully matched to the gallons per minute flow rate of your spa. When it is time to replace your filters, remember only Caldera filters have been specifically designed to ensure your spa has clean, sparkling water day after day. Caldera Pre 2003 Models - 50 sq. ft.
Reminder: it is recommended that you replace each filter in your hot tub at the same time.