Why cleaning your filter changes everything
A clean filter means fewer products, fewer breakdowns, and water that stays looking good for longer. But between a regular backwash and a real deep clean, many pool owners get confused. Here's the difference.
Backwash vs deep cleaning
- Backwash: 5 minutes, weekly/monthly, clears out the big dirt. This is routine maintenance.
- Chemical cleaning: 30 to 60 minutes, once or twice a year, removes oils, sun cream, limescale and scale.
The two are complementary: without a deep clean, the sand gradually clogs and backwashing loses its effectiveness.
Sand filter: the method
1. A classic backwash first. 2. Partial drain of the filter (via the bottom plug). 3. Pour a filter cleaner specific to sand into the skimmer basket or directly into the tank, depending on the product. 4. Recirculate for 1 to 2 hours (valve on Recirculation, not Filtration). 5. Leave to work for 8 to 12 hours, pump off. 6. Thorough backwash + rinse to flush out the product.
Do this before the spring start-up: that's when it has the maximum effect.
Cartridge filter: the method
1. Remove the cartridge. 2. Hose it down, fold by fold, to loosen the big deposits. 3. Soak for 8 to 12 hours in a tub with a degreasing product specific to cartridges. 4. Rinse thoroughly before refitting.
Two cartridges in rotation is ideal: while one soaks, the other filters.
When to hand it over to a professional
Three situations:
- You don't know where the filter drain is, or how to set the valve for each step.
- You've done it, but the pressure won't come back down → the sand probably needs changing.
- It's been more than 4 years since you changed the sand or cartridge → this is the moment to combine both jobs.
A professional filter clean costs €149, a fixed price, and restores 100% of the original performance.
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Start my diagnosisFrequently asked questions
How often should you clean a pool filter?+
Backwash: as soon as the pressure rises 0.3 to 0.5 bar (typically 1 to 2 times a month in summer). Deep chemical cleaning: at least once a year, ideally twice for heavily used pools.
What product should you use to clean a sand filter?+
A degreaser specific to sand filters, or an anti-limescale product if the water is very hard (common in the Var). Never bleach or household cleaning products: they damage the sand and the parts.
Can you clean a cartridge in the dishwasher?+
No, the detergent damages the fibres. Soaking with a dedicated product plus a hose rinse is the right method.
How much does a professional filter clean cost?+
€149, a fixed price whatever the filter type. Often combined with a water check to confirm the turbidity problem really was the filter.
The related service
Filter cleaning
A clean filter means half the chemicals.
149 € · 45 min to 1 hr 30
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