AquaFinesse filter cleaner tablets (200g, 10 tablets). 

To maximize the enjoyment of your Aquafinesse water care products, it is essential to keep your filters clean, and to do this we recommend cleaning your filters at least once a week.  We have developed a specially formulated filter cleaning tablet to better assist you with this process and keep your filters in optimal condition.

Hot Tub Filter Cleaner Tablets
Filter Cleaner tablets help keep filters working at their optimal level. Cleans cartridge filters in a fraction of the time it takes conventional cleaners.
No overnight soaking required. Individually wrapped tablets for safe handling and no mess.

Environmentally friendly.

Packaged in jars containing 10 tabs

Alternative: Spa Marvel Filter Cleaner or Cartridge Cleaner

https://dynastyspasparts.com/spa-marvel-filter-cleaner/

https://dynastyspasparts.com/cartridge-cleaner/