Unicel C-4405 2-Pack | 50 sq ft Rainbow DSF Spa Filter Brand_Vermont Castings This kit handles both in

This kit handles both in the right order

Pro Tip: Check the thread size

Ooni Pizza Cutter Wheel

and a spa that never quite gets "clear" no matter how much chemistry you add

Unicel C-4405 2-Pack | 50 sq ft Rainbow DSF Spa Filter Brand_Vermont Castings This kit handles both inThe Unicel C 4405 is a matched pair of replacement filter cartridges delivering 50 square feet of combined filtration for Pentair Rainbow Dynamic Series IV systems and Waterway skim filters. It is sold as a set of two because the system is designed around two cartridges working side by side not because two is a convenient bulk quantity. That distinction matters more than it might sound. These housings run a pair of compact cartridges in parallel