80% of Pool Filter Cartridges Clogged Because of This Operation?

One、The invisible killer cartridge clogging: improper shutdown operations

1. When you press the stop button of the pool pump, fatal changes are occurring inside the cartridge:

Sediment back up: the water flow is reversed at the moment of shutdown, and the dirt retained by filtration is washed back to the deeper layer of the cartridge (especially in the traditional sand cylinder filtration system).

2. Biofilm breeding: the organic matter left in the cartridge forms a sticky biofilm in the static water temperature for 24 hours, and adsorbs new impurities to form the gelatinous clogging layer.

3. Calcification and crystallisation: calcium and magnesium ions in the residual water in hard water areas deposit in the folds of filter paper, as if ‘pouring cement’ to the filter cartridge. Magnesium ions are deposited in the folds of the filter paper, just like ‘pouring cement’ to the filter cartridge.

Two、Clogging warning signals: your cartridge is asking for help

When any of the following symptoms are present, the blockage rate has exceeded the safety threshold:

✅ Pump pressure gauge consistently above 1.5 bar (normal 0.8-1.2 bar) 

✅ Backwash more than 2 times per week 

✅ Darkening/yellowing of cartridge pleats visible to the naked eye (normal light grey) 

✅ Decrease in suction at the bottom of the pool of more than 30%

Three、Professional level protection operation: 2 steps to save the life of the cartridge

Step 1: Decompression before shutdown (key!)

Before switching off the pump, turn the multi-function valve to ‘RECIRCULATE’ and run it for 60 seconds, so that the residual dirt in the pipeline can be drained straight back to the swimming pool.

Step 2: Deep Venting 

Open the pressure relief valve at the top of the canister until no water vapour is emitted (to prevent airlocks from creating a vacuum that traps impurities)