Filter Cartridge Cleaner

Restore filter flow and trapped-debris capacity overnight. A concentrated alkaline cleaner that strips body oils, sun cream and hard-water deposits from pleated filter cartridges.

• Dissolves body oils, lotions and grease in a single overnight soak.
• Removes mineral scale build-up between the pleats.
• Restores up to 90% of original filter flow rate.
• Extends cartridge life by 2-3 cleaning cycles before replacement.
• Will not damage paper or polyester filter media when used as directed.

Sizes and prices

• 1L: £7.22
• 2.5L: £12.76
• 5L: £21.99
• 10L: £40.45
• 20L: £77.38
• 25L: £95.84

When you need it

• Filter pressure has risen 25 kPa above the clean baseline.
• Jets feel weaker than normal even with a full pump cycle.
• Visible grime is matted between the pleats after a hose down.
• Water clarity falls within hours of refilling.
• Cartridge has not been deep-soaked for 4 weeks or more.

How to use

1. Switch the hot tub off at the isolator and remove the filter cartridge.
2. Hose down the cartridge from the inside out to remove loose debris.
3. Mix 1 part Filter Cartridge Cleaner with 10 parts warm tap water in a clean bucket.
4. Submerge the cartridge fully in the diluted solution overnight (8-12 hours).
5. Rinse thoroughly with fresh water until no foam appears.
6. Allow to drip-dry for 1 hour before refitting and switching the spa back on.

Dosing guide

Standard 1:10 dilution suits most cartridges. For very heavy soiling extend the soak to 24 hours rather than increasing the concentration.

• For 5 L bucket, add 500 ml to reach Standard soak.
• For 10 L bucket, add 1,000 ml to reach Standard soak.
• For 20 L bucket, add 2,000 ml to reach Twin cartridges.
• For 5 L bucket, add 250 ml to reach Light maintenance.
• For 10 L bucket, add 1,500 ml to reach Heavy soiling.

How it works

A balanced blend of non-ionic surfactants, alkali builders and chelating agents formulated to lift organic and mineral soiling without attacking polyester or paper filter media.

Surfactants emulsify the body-oil and lotion film that coats the pleats; chelators bind calcium and iron in the scale layer; alkali builders raise pH around the soiling so the trapped mineral and organic matrix releases cleanly. The pleats are then rinsed clean and the original surface area restored.

Hot-tub cartridges trap body oils within hours. Within 4 weeks, oils glaze the pleats and trap scale, dropping filtration efficiency by 40-60%. A 12-hour overnight soak restores flow, cuts pump strain and reduces sanitiser demand.

Frequently asked questions

How often should I deep-soak the cartridge?

Every 4 weeks for a domestic hot tub; every 2 weeks for a spa with high bather load.

How long should I soak the cartridge?

8-12 hours overnight is ideal. Do not exceed 24 hours.

What is the dilution ratio?

1 part concentrate to 10 parts warm tap water for standard soiling.

How many soaks does 1 L cover?

Approximately 10 standard soaks of a single cartridge in a 10 L bucket.

Is it safe for paper or polyester pleats?

Yes. The blend is pH-balanced for both materials when diluted as directed.

Will it remove calcium scale?

Yes. The chelators bind calcium and iron, lifting scale alongside organic soiling in the same soak.

Why does cleaning matter for sanitiser use?

A clogged filter circulates less water, so sanitiser is not distributed evenly. Cleaning restores even contact and cuts sanitiser demand.

What pH is the diluted solution?

Approximately pH 10.5 at 1:10 dilution. Strong enough to lift soiling, mild enough for filter media.

Can I use it in a dishwasher?

No. The cleaner is formulated for filter media, not for hard surfaces, and dishwasher heat will degrade it.

Cartridge still smells after rinsing?

Soak again in fresh dilute solution; if smell persists, the cartridge is at end of life.

Foam appearing after refitting?

Surfactant residue remains. Rinse thoroughly and dose 25 ml Foam Away per 1000 L.

Pressure rises again within a week?

Bather load is high or sanitiser is below band. Test sanitiser and shock if needed; clean cartridge weekly.

Cleaner vs filter granules?

Cleaner is for cartridges; granules are for sand or in-tub filter elements that cannot be removed.

Cleaner vs hot tub flush?

Hot tub flush cleans the pipework; cartridge cleaner cleans the removable filter element. Use both during full water changes.