In stock · ships freeClarisink RO-300 Compact Reverse Osmosis System
£179.00
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
The RO-300 is the entry point into reverse osmosis. It drops one carbon stage and uses a smaller tank, which brings the footprint down to something that fits under a sink already crowded with a waste trap, a bin and cleaning products.
You still get the membrane, which is the stage that actually matters. Dissolved solids, lead and scale-forming minerals are removed the same way they are on the larger units. What you give up is a little chlorine-taste polish and the ability to draw a lot of water quickly.
For a one or two-person household that mainly wants clean drinking and cooking water, that is a reasonable trade. For a family getting through several litres a day, the RO-400's larger tank is worth the extra.
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
- 0.0001 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 stages | 3 (sediment, carbon block, RO membrane) |
|---|---|
| Membrane rating | 0.0001 micron |
| Rated output | 300 GPD (approx. 1,100 litres per day) |
| Tap flow rate | approx. 1.0 litre per minute |
| Storage | Pressurised tank, approx. 1.8 gallons / 7 litres |
| Waste-water ratio | approx. 3:1 |
| Pre-filter life | 6-12 months |
| Membrane life | 2-3 years |
| Power required | No — mains water pressure only |
| Under-sink footprint | approx. 34cm W x 42cm H x 18cm D, plus tank |
| Minimum mains pressure | 2.8 bar |
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
- Dissolved solids (TDS)
- Chlorine
- Heavy metals including lead
- Sediment and particulates
What it will not do
- Three stages rather than four means one less carbon stage, so chlorine taste removal is good but not quite as thorough as the RO-400.
- The smaller 7-litre tank refills more slowly. A household filling several bottles back to back will notice.
- Highest waste-water ratio of the three systems.
- No remineralisation — expect the flat taste characteristic of plain RO water.
- Filters one tap only.
Will this fit?
Check these before you order — they are the questions we are asked most often.
- Requires a 35mm sink or worktop hole for the included chrome tap
- Needs a waste-pipe connection for the drain line
- Takes replacement cartridge AF-RO400M (membrane) and AF-CBC1 (carbon block)
Still not sure? Send us your sink and pipework details and we will confirm before you buy.
Not sure which RO system?
The RO-300, RO-400 and RO-500 differ on output, footprint, waste water and whether they need a power socket. Compare all three side by side before you commit.
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