Important: Prices, availability and specifications can change. We use manufacturer-published information and recommend confirming current details before buying.
How we compare RO systems
AVERQUA compares purchase price, flow/capacity, pure-to-drain or recovery information where published, installation format, filter replacement structure and manufacturer-published testing or certification information. We do not claim to have independently laboratory-tested these systems.
PriceCurrent UK manufacturer-listed price when available.
OutputDaily capacity or GPD rating stated by the manufacturer.
EfficiencyPublished drain ratio or recovery information where available.
MaintenanceFilter format, replacement schedule and installation complexity.
| Product | Best for | Price checked | Output | Format |
|---|
| AQUAPHOR Osmo Pro 50 | Lowest-cost traditional RO | £129.99 | Traditional membrane system | 10 L storage tank |
| AQUAPHOR RO-101S | Compact household RO | £249.99 | 190 L/day | Quad-stage, dedicated tap |
| Waterdrop G2P600 | Value tankless RO | £249.99 | 600 GPD | Tankless |
| Frizzlife PD400 | Compact tankless | £279.99 | 400 GPD | 5-stage, tankless |
| Waterdrop G3P600 | Smart high-flow option | £399.99 | 600 GPD | Tankless, smart faucet |
| Ecosoft CROSS90 | Slim high-flow system | Check stockist | 600 GPD / 1.5 L/min stated | Direct-flow tankless |
| AQUAPHOR RO-202S | Pumped premium setup | £549.99 | 380 L/day | Integrated pump |
Budget traditional RO
AQUAPHOR Osmo Pro 50
£129.99*
A lower-cost traditional reverse-osmosis setup using a 10-litre storage tank, aimed at households that prioritise purchase price over a compact tankless format.
Pros- Lowest listed purchase price in this comparison
- Traditional, familiar RO layout
- Dedicated drinking-water supply
Consider- Storage tank uses more cabinet space
- Lower-output format than modern high-GPD systems
- Check replacement-filter costs before buying
*Manufacturer-listed price checked 1 October 2026. Illustrative product graphic.
Compact household RO
AQUAPHOR RO-101S
£249.99*
A quad-stage under-sink RO system with a dedicated drinking-water faucet and a manufacturer-stated capacity of 190 litres per day.
Pros- Compact household-focused system
- Dedicated faucet included
- Clear manufacturer capacity figure
Consider- Lower output than 400–600 GPD tankless systems
- Dedicated tap installation required
- Confirm cabinet-space requirements
*Manufacturer-listed price checked 1 October 2026. Illustrative product graphic.
Value tankless
Waterdrop G2P600
£249.99*
A compact 600 GPD tankless RO option positioned below Waterdrop’s premium G-series systems, useful for households wanting higher stated output without a storage tank.
Pros- 600 GPD stated output
- No storage tank
- Lower price than Waterdrop G3P600
Consider- Electricity required for most tankless high-flow RO formats
- Check current stock status
- Replacement costs matter over time
*Manufacturer-listed price checked 1 October 2026. Illustrative product graphic.
Compact tankless
Frizzlife PD400
£279.99*
A 400 GPD tankless system with manufacturer-stated five-stage 0.0001 μm RO filtration and a compact under-sink design.
Pros- Compact tankless design
- Clear 400 GPD output rating
- Lower upfront price than many premium tankless systems
Consider- Current Frizzlife UK availability can vary
- Lower stated output than 600–800 GPD models
- Requires drain connection and power
*Manufacturer-listed price checked 1 October 2026. Illustrative product graphic.
Smart high-flow
Waterdrop G3P600
£399.99*
A 600 GPD tankless RO system with a smart faucet, manufacturer-stated 2:1 pure-to-drain ratio and published NSF/ANSI 42, 53, 58 and 372 certification information.
Pros- High stated output
- Smart faucet monitors TDS/filter life
- Published certification information
Consider- Higher purchase price
- Electricity required
- Multiple replacement filters
*Manufacturer-listed price checked 1 October 2026. Illustrative product graphic.
Slim direct-flow
Ecosoft CROSS90
Check stockist
A slim 600 GPD direct-flow RO system with a manufacturer-stated 1.5 L/min pure-water flow, recovery above 50%, smart flushing and filter-life/water-quality indication.
Pros- Slim 140 mm stated width
- Smart flushing and filter-life indication
- High stated output
Consider- UK direct retail pricing is not obvious from the manufacturer page
- Requires power and drain connection
- Check local stockist support
Manufacturer technical data checked 1 October 2026. Illustrative product graphic.
Pumped premium
AQUAPHOR RO-202S
£549.99*
A quad-stage under-sink RO system with an integrated pump, a dedicated faucet and a manufacturer-stated capacity of 380 litres per day.
Pros- Integrated pump for consistent operation
- Higher output than RO-101S
- Dedicated faucet included
Consider- Highest listed price in this comparison
- More complex powered installation
- Check replacement cartridge costs
*Manufacturer-listed price checked 1 October 2026. Illustrative product graphic.
How to choose between these RO systems
Lowest upfront cost
A traditional tank system can cost much less than a premium tankless model, but it uses more cabinet space and generally delivers water differently.
Compact + fast flow
Tankless 400–600 GPD systems suit households that value cabinet space and higher stated output, but they normally require electricity and a drain connection.
Water efficiency
Compare published drain ratios or recovery rates. A high GPD number alone does not tell you how much reject water a system produces.
Frequently asked questions
Does reverse osmosis reduce dissolved solids?
That is one of the main reasons households compare RO with carbon or ultrafiltration systems. Check the exact manufacturer performance claims for the product you are considering.
Do tankless RO systems need electricity?
Many high-flow tankless systems use pumps, sensors or electronic faucets and therefore require power. Check the installation requirements for the exact model.
Does every RO system waste the same amount of water?
No. Manufacturers publish different pure-to-drain ratios or recovery rates. Compare those figures rather than assuming all RO systems are equally efficient.
Do I need a plumber?
RO installation normally involves the cold-water line, a dedicated drinking-water faucet and a drain connection. A competent installer may be preferable if you are not comfortable modifying plumbing or worktops.
