Three-stage under-sink drinking water filtration
Cleaner-tasting drinking water for soft water areas
The Aquaphor Crystal is a compact under-sink filtration system designed for homes with naturally soft or already softened mains water. Its K3, K2 and K7 cartridges reduce chlorine, unpleasant taste and odour, sediment, organic compounds and heavy metals while retaining the water's natural mineral composition.
Compact everyday filtration
Fresh filtered water from a dedicated kitchen tap
Installed beneath the kitchen sink, the Crystal provides filtered water for drinking, cooking and hot drinks without taking up worktop space. The supplied drinking water tap keeps filtered water separate from the normal hot and cold supply.
- Three-stage K3, K2 and K7 filtration
- Up to 2.5 litres per minute
- Up to 8,000 litres per cartridge set
- Fine filtration down to 0.8 micron
- Tool-free Auto Lock cartridge changes
Filtration stages
K3, K2 and K7 cartridges work in sequence.
Fast flow
Filters up to 2.5 litres of water per minute.
Filter capacity
Up to 8,000 litres, subject to water quality.
Final filtration
The K7 stage filters particles down to 0.8 micron.
K3, K2 and K7 filtration
Three specialist cartridges, one compact system
K3 cartridge
Preliminary sorption treatment
Reduces active chlorine, organic impurities, heavy metals and particles down to 5 microns. It also provides increased capacity for colloidal and dissolved iron.
K2 cartridge
Deep sorption treatment
A denser Aqualen carbon block reduces active chlorine, organic impurities and heavy metals while filtering particles down to 3 microns.
K7 cartridge
Final treatment and conditioning
The final polishing stage reduces residual organic compounds and heavy metals and filters fine particles down to 0.8 micron.
Aqualen carbon block technology
High contact area for effective contaminant reduction
Each CarbFiber module combines activated coconut shell carbon with Aquaphor's patented Aqualen ion-exchange fibre. This structure increases contact between the water and filtration media, helping the system reduce chlorine, lead and other heavy metals, pesticides, petroleum products, phenols and other common tap water impurities.
Silver is immobilised within the Aqualen fibre to help maintain the filter media. It is not added to the filtered water as a separate treatment chemical.
What the Crystal improves
Practical filtration for drinking and cooking
The Crystal is a sorption filter for municipally treated water. It improves the qualities most people notice at the kitchen tap while also targeting less visible contaminants.
Chlorine reduction
Helps improve the taste and smell of mains drinking water.
Heavy metals
Aqualen ion-exchange fibre targets lead and other heavy-metal ions.
Fine particles
Three progressively finer stages reduce rust, sediment and suspended material.
Organic impurities
Carbon filtration reduces pesticides, phenols and petroleum-derived compounds.
Choose the correct Crystal model
Designed for soft water areas
This standard Crystal does not contain the KH water-softening cartridge. Choose it where the incoming water is already soft or where drinking water has been taken from a softened supply. If limescale is the main issue, use a system specifically designed for hard water.
Technical information
Aquaphor Crystal specification
| System type | Three-stage under-sink sorption filter |
|---|---|
| Recommended water type | Soft or already softened municipally treated water |
| Cartridge sequence | K3, K2 and K7 |
| Filtration rate | Up to 2.5 litres per minute |
| Cartridge-set capacity | Up to 8,000 litres, depending on incoming water quality and use |
| Finest filtration stage | 0.8 micron through the K7 cartridge |
| System weight | Approximately 2.85 kg |
| Cartridge replacement | Tool-free Auto Lock twist-and-click system |
| Drinking water tap | Included |
| Tap-hole requirement | 12 mm, according to the installation manual |
| Installation supply | Cold water only |
| Pressure guidance | Fit a pressure-reducing valve if incoming pressure exceeds 0.63 MPa / 6.3 bar |
| System service life | Five years from manufacture, excluding replaceable cartridges |
| System warranty | Two years, excluding replaceable cartridges and subject to the manufacturer's terms |
Installation and maintenance
Download the Aquaphor Crystal manual
Review the connection layout, 12 mm tap-hole requirement, cartridge order, flushing procedure and safety guidance before installation.
Replacement filters
Maintain performance with the correct cartridge set
Use the K3, K2 and K7 set
The three cartridges must be installed in the correct order. Aquaphor promotes annual replacement, while the manual gives an upper service limit of 8,000 litres or 1.5 years for this set. Poor incoming water quality or high usage can require earlier replacement.
Understand what you are buying
A carbon filtration system, not reverse osmosis
Soft mains water
Reduces common impurities while keeping the water's natural mineral composition.
Hardness removal
The standard Crystal does not soften water or prevent scale caused by dissolved hardness minerals.
No membrane or waste water
It uses three carbon-based cartridges and does not produce the demineralised water associated with reverse osmosis.
Related products
Browse compatible filters and drinking water systems
Compare under-sink purification systems or find the correct Aquaphor replacement cartridges for ongoing maintenance.
Helpful answers
Frequently asked questions
Is the Aquaphor Crystal a reverse osmosis system?
No. The Crystal is a three-stage sorption filter using K3, K2 and K7 carbon-based cartridges. It does not use an RO membrane, storage tank or waste-water connection.
Is this model suitable for hard water?
No. This version is intended for naturally soft or already softened water. It reduces contaminants but does not remove the calcium and magnesium responsible for limescale.
What does the Aquaphor Crystal reduce?
It is designed to reduce chlorine, unpleasant taste and odour, sediment, rust, organic compounds, pesticides, petroleum products, phenols and heavy metals. The K7 final stage filters particles down to 0.8 micron.
How quickly does it filter water?
The published filtration rate is up to 2.5 litres per minute when installed and operated under suitable conditions.
How often should the filters be replaced?
Aquaphor promotes cartridge replacement once a year. The manual gives a maximum capacity of 8,000 litres and a maximum service period of 1.5 years for the K3, K2 and K7 set. Replace sooner if the flow falls, taste or odour returns, or incoming water quality is poor.
Does the system include a drinking water tap?
Yes. A separate filtered-water tap, connecting tubes, connection unit and K3, K2 and K7 cartridges are included. The manual specifies a 12 mm hole for the supplied tap.
Can I connect the Crystal to hot water?
No. It must be connected to the cold water supply and kept away from heat sources such as hot-water pipes, ovens, boilers, washing machines and dishwashers.
Friendly expert support
Not sure whether the Crystal suits your water?
Tell us your postcode, whether your water is softened and what you want to improve. We will help you choose the appropriate under-sink system before ordering.