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Clarisink Limescale Defender under-sink filterIn stock · ships free
Limescale Filter

Clarisink Limescale Defender Under-Sink Filter

£149.00

VAT included · Free UK delivery · Typically arrives in 4–21 business days

  • Shipped via UK Tracked Delivery
  • 60-Minute Simple DIY Setup
  • 2-Year Comprehensive Warranty
  • Engineered for Hard UK Tap Water

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  • Free UK delivery on every order, no minimum spend
  • 2-year warranty on all filtration systems
  • 30-day returns if it isn't right for your kitchen
  • Fits a standard UK cold feed — no plumber required
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Best under sink water filter UK families can rely on

Finding the best under sink water filter uk families can rely on is essential if you want to eliminate cloudiness, chemical odours, and heavy limescale from your daily kitchen tap water.

About this product

If you live in London, the South East or East Anglia, your water is hard, and the symptoms are familiar: a chalky ring in the kettle, cloudy glassware, and a boiler that costs a little more to run every year. The Limescale Defender targets that specific problem.

It works by sequestration. A polyphosphate cartridge holds calcium and magnesium in suspension so they stay dissolved instead of crystallising out onto heating elements and tap fittings. Alongside it, a carbon block deals with chlorine so the water tastes better as well.

Be clear about what this is and is not. It is not a water softener — the minerals are still in the water, they simply stop depositing. That is usually what people actually want, because softened water has its own drawbacks and a full softener is a considerably bigger installation.

For dissolved solids, fluoride or lead, this is the wrong product and reverse osmosis is the right one. For scale and taste in a hard-water postcode, it is the simpler and cheaper answer.

Dispatched from our UK warehouse, with delivery in 4-21 business days depending on the item. That is slower than a next-day marketplace and we would rather say so up front than surprise you at the door.

Technical specifications

Connection size
Standard UK 15mm push-fit / compression
Micron rating
5 micron
Lifespan
6 months or 4,000 litres (whichever comes first)

Litres and centimetres are used throughout. Cartridge life is measured in litres of filtered water, so heavily used households will change theirs sooner.

Specifications

Filtration stages2 (carbon block + polyphosphate scale inhibitor)
Filtration rating5 micron
Flow rateapprox. 3.8 litres per minute
Cartridge capacityapprox. 8,000 litres
Cartridge lifeapprox. 12 months
Housing sizeStandard 10-inch
Power requiredNo
Waste waterNone
Under-sink footprintapprox. 13cm W x 35cm H x 13cm D

Figures marked with this symbol are provisional and are being confirmed against the manufacturer's datasheet. We publish them as estimates rather than leaving the row blank, and we do not claim any certification or test result we cannot evidence.

What this filter addresses

  • Scale-forming behaviour of calcium and magnesium (sequestered, not removed)
  • Chlorine and chlorine taste
  • Sediment and particulates

What it will not do

  • This is scale inhibition, not softening. The polyphosphate stops calcium and magnesium from crystallising and sticking to surfaces — it does not take them out of the water. A hardness test will read the same before and after.
  • It does not reduce dissolved solids, fluoride or nitrates. If that is your goal, you need reverse osmosis.
  • It protects the appliances downstream of the filter only. A whole-house scale problem needs a mains-position unit.
  • Polyphosphate is depleted by use rather than by time, so heavy-use households will need the cartridge sooner than 12 months.

Will this fit?

Check these before you order — they are the questions we are asked most often.

  • Standard 10-inch cartridge housing
  • Takes replacement cartridge AF-LSC1
  • Pairs with the AF-TAP3C 3-way tap, or use your existing tap with a separate filter faucet

Still not sure? Send us your sink and pipework details and we will confirm before you buy.

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