Caldera 73531 | 75 sq ft Utopia Spa Filter Type_Pizza Oven Keeping a fresh mineral cartridge

Keeping a fresh mineral cartridge on hand (or on autoship) is the cheapest insurance against chemistry drift

Both metals are invisible in solution

Pro Tip: Enzymes are about prevention

and other non-living organic materials that build up in spa water and create that frustrating scum line at the waterline

which sanitizes the water and then reverts to bromide — going back into the bank to be reactivated again

Caldera 73531 | 75 sq ft Utopia Spa Filter Type_Pizza Oven Keeping a fresh mineral cartridgeThe Caldera 73531 filter cartridge is a factory original replacement covering a wide range of Caldera spas. With 75 square feet of filtration across 260 pleats of heavy duty polyester, it delivers more efficient filtration and better water clarity so you spend less time cleaning and more time enjoying your hot tub. Filtration is the quiet backbone of good spa water. Every soak leaves behind body oils, lotions, hair, and fine debris, and the cartridge