Benefit of having a cartridge filter for spas:
Cartridge filters are much smaller than sand filters which is the alternate option for spas;
Cartridge filters remove finer debris from water than sand filters, thus filtrates better;
Heat-loss through the filter housing is less than with a sand filter due to the smaller outside surface area;
Cleaning of cartridge filters takes less water than the “backwash & rinse cycle” of sand filters;
Finally its uses up less space in a compact pump-box and is nowadays commonly installed in jacuzzi’s / spas.