Spa Filtration

Cartridge filters are the most frequently replaced hot tub part — and the most common cause of problems when replaced too late. This category carries over 290 Darlly and Pleatco filter cartridges in all common sizes, including antibacterial Darlly Microban versions, plus fill-hose pre-filters. What's in stock Darlly SC-series filter cartridges — from small cartridges up to SC895–SC899 for large hot tubs Pleatco cartridges (PRB50-IN, PWW50-XP4, PJZ16-F2L, PSN50L-P4 and more) with stated dimensions in mm Threaded and smooth-bore cartridges SpaLine Spa Pre-Filter — a fill-hose pre-filter that catches debris from the mains water before it reaches the tub How to choose the right cartridge Hot tub brand won't help you, dimensions will. Measure three values on the old cartridge: outer diameter, overall length and bore diameter — and check whether the cartridge has a threaded base (for example Pleatco PJZ16-F2L uses a 57 mm thread) or just a smooth bore. We list dimensions for every catalogue item — for instance, the Pleatco PRB50-IN measures 338 × 127 × 54 mm. The same cartridge often has different codes across manufacturers — if you only have a code you can't find, contact us and we'll find the Darlly or Pleatco equivalent. What to watch out for A clogged filter is the most common cause of a flow error (FLO) on the display and the heater switching off — before ordering new control system parts or a pump, try a new cartridge first. Rinse the cartridge roughly every 1–2 weeks depending on use, and replace it about once a year; paper pleats that stay stuck together even after washing no longer filter the water. You can reduce the load on the filter with supplementary disinfection — see our ozonators and UV category. For whom Swapping a cartridge takes a minute and needs no tools — this category is for any hot tub owner who wants to keep the water clean and the heating working without calling a service technician. For wellness and hotel operators, we recommend keeping two sets of cartridges and rotating them. In-stock cartridges ship within 48 hours across the EU.