Cartridge filters for swimming pools

Pool cartridge filters provide filtration down to 20 to 25 microns, compared with the 40 or 50 microns typical of silica sand beds. Their compact design eliminates the need for backwashing to the drain, trapping dirt in a pleated polyester membrane that can be cleaned simply with pressurized water.

This feature saves thousands of liters of chemically treated water each season. If you’re looking for comprehensive pool equipment, our catalog includes options such as the Star 300 sand filter with pump for conventional installations, although a cartridge filter is indispensable when there is no direct outdoor drainage outlet.

During installation, make sure the pump’s flow rate does not exceed the cartridge’s capacity to prevent structural deformation of the plastic core. Connect leak-proof 32 mm or 38 mm hoses, depending on the return and suction nozzle connections.

Consider the following installation guidelines before switching on the system:

• Completely bleed the air trapped in the top lid using the manual bleed valve until a steady stream of water flows out.
• Check that the initial pressure gauge reading is below 0.6 bar with a clean cartridge.
• Avoid running the pump dry to prevent thermal damage to the mechanical seal.

The system operates in a closed loop, trapping impurities without sending a single liter of water outside.

Standard liquid flocculant should not be used in cartridge filters because it clumps microscopic particles together, irreversibly clogging the pores in the polyester fabric. This blockage rapidly increases internal pressure and means the replacement cartridge has to be changed prematurely.

To clarify the water in these systems, use specific enzymatic coagulants or clarifying tablets designed not to adhere to synthetic fibers. If the water is extremely cloudy or contains compacted dirt, apply chemical shock treatments and brush the walls before recirculating.

Cleaning should be carried out as soon as the pressure gauge registers an increase of between 0.3 and 0.5 bar compared with the operating pressure when the filter is clean. Stop the pump, release the pressure by opening the lid’s bleed valve, and remove the cylindrical filter element.

Follow these maintenance steps to ensure it lasts:

• Spray it with water from a garden hose, working from top to bottom and separating each polyester pleat to remove leaves and sediment.
• Soak the cartridge in a cartridge descaling solution if you notice whitish limescale deposits.
• Inspect the seals and cartridge body before reinserting it to make sure there are no cracks.

Rinsing it every 15 or 20 days during the summer season keeps the flow rate steady without overloading the pump.

A cartridge typically lasts 1 to 2 full seasons in residential pools, depending on the dirt load and water hardness. It should be replaced when the fabric is torn, the pleats are permanently deformed, or the pressure remains high despite a thorough chemical cleaning.

Continued use of worn elements allows fine impurities to pass into the pool and puts extra strain on the motor’s suction power. Checking the condition of the upper and lower plastic caps ensures that water flows through the filter fabric and not untreated through the sides.

Hayward’s monobloc cartridge systems are designed for high flow rates and in-ground pools or large-volume spas, providing a larger filtration area in highly chemical-resistant housings. Gre’s solutions, on the other hand, are well suited to tubular and removable above-ground pools, where easy connections and straightforward maintenance are priorities.

If you have a removable pool with a surface skimmer, components such as the Skimmer + AR100 impulse nozzle ensure the hydraulic compatibility required for low-power pumps. Assess the total water volume to determine how many square meters of polyester your system needs.

Cartridge filtration systems are fully compatible with salt chlorination and disinfection treatments using traditional chlorine or bromine. Since they have no complex metal valves or lower laterals exposed to constant sand abrasion, their injection-molded polypropylene housings easily withstand standard salt concentrations of 4 to 6 grams per liter.

Simply make sure that salt buildup in the microfibers does not cause the fabric to stiffen prematurely. To prevent this, rinse the cartridge with fresh water more frequently during the summer and maintain the concentration recommended by your chlorinator’s manufacturer.