Product Price Filter Capacity (gallons) Flow Rate (GPM (Gallons Per Minute)) Contaminant Removal Installation Difficulty Warranty (years) Water Pressure Requirement (PSI (Pounds per Square Inch))
APEC APEC ROES-50 Essence Series Reverse Osmosis System
US
£158.36 50 gallons per day Removes up to 99% of contaminants Easy to moderate (DIY under-sink installation) 2 year extended manufacturer warranty with registration 40-85 psi

Five-stage under-sink RO system that produces up to 50 gallons per day, includes a 4 gallon tank and designer faucet, and is WQA Gold Seal certified for high contaminant rejection. Suited for homeowners wanting high-purity drinking water and DIYers comfortable with standard under-sink installation.

Clearly Filtered Clearly Filtered 3-Stage Under-Sink Filtration System
US
£368.58 2000 gallons 1.08 GPM 232+ contaminants 100% DIY; all you need is a wrench Limited lifetime warranty (warranted for 24 months) Designed for standard residential water pressure (~60 psi)

Three-stage under-sink system using Affinity filtration to remove a wide range of contaminants while retaining beneficial minerals. Suits homeowners or renters who want high contaminant removal without a separate faucet and prefer a DIY install.

Cloud Ro Cloud RO Under-Sink Reverse Osmosis System
US
80 GPD 0.05 GPM reduces TDS and up to 99% of many contaminants including lead fluoride PFAS pesticides pharmaceuticals moderate DIY (30-60 minutes) 1 year 50 PSI (tested at 50 PSI)

Compact under-sink RO with a stacked tank, integrated remineralization and app monitoring. Suited for homeowners wanting high-purity alkaline drinking water with moderate DIY installation.

iSpring iSpring RCC7AK 6-Stage Reverse Osmosis System
US
£174.97 75 GPD Removes up to 99% of over 1,000 contaminants including fluoride, lead, arsenic, asbestos, chromium, copper, TDS DIY friendly; push-to-connect fittings and color-coded tubing simplify installation 1 year limited manufacturer warranty (upon registration) 40-85 psi

6-stage under-sink RO with alkaline remineralization producing up to 75 gallons per day and restoring healthy minerals for better taste. Suited for households wanting high contaminant reduction and bottled-water quality on tap.

NU Aqua NU Aqua Under Sink Reverse Osmosis System 5-Stage
US
£148.88 100 GPD Up to 99% of contaminants No plumber needed, easy installation (under an hour) 3 Year Warranty

5-stage under-sink reverse osmosis system rated for 100 gallons per day with multi-stage carbon and RO membrane filtration. Suited for households needing high daily output and comprehensive contaminant reduction, with simple DIY installation and a supplied storage tank and faucet.

Waterdrop Waterdrop G3P600 6-Stage Reverse Osmosis System
US
£292.82 600 GPD TDS, PFAS, fluoride, lead, chromium-6, chlorine (reduces a wide range of contaminants) DIY install ~30 minutes (requires under-sink power)

Tankless under-sink RO that produces 600 gallons per day with an on-demand fast flow, smart LED faucet and multi-stage filtration to remove PFAS, heavy metals, fluoride and reduce TDS; suited for households wanting high-capacity, space-saving, high-performance filtration.

Waterdrop Waterdrop G3P800 Tankless Reverse Osmosis System
US
£632.16 CF filter up to 6 months or 550 gallons; CB filter up to 12 months or 1100 gallons; RO filter up to 24 months or 2200 gallons 800 GPD Removes PFAS, fluoride, lead, chromium and heavy metals; NSF/ANSI 42, 53, 58, 372 certified DIY under-sink, approximately 30 minutes 1 year 60 PSI recommended

Tankless under-sink RO system with 10-stage filtration and UV sterilization producing up to 800 GPD; includes smart faucet with real-time TDS display. Suited for households who want high-flow RO water on demand and space-saving installation.