Does reverse osmosis waste a lot of water?

Modern tankless RO systems like the Waterdrop G3P600 have a 3:1 pure-to-waste ratio, meaning 3 litres of clean water for every 1 litre wasted. Older systems can be less efficient.

Does reverse osmosis remove minerals I need?

RO removes most dissolved minerals. Some systems add minerals back with a remineralisation stage. For most people, a balanced diet provides enough minerals without relying on tap water.

Reverse Osmosis Systems

The gold standard. RO systems push water through a semi-permeable membrane, removing virtually everything.

Best for: Households with PFAS, fluoride, or nitrate concerns · £329–£499

Read our full guide: Best Reverse Osmosis System UK

Not sure which to pick? Check your water first.

Try your postcode — e.g. SW1A, M1, B1

Waterdrop G3P600 Reverse Osmosis

Reverse Osmosis · NSF/ANSI 58, NSF/ANSI 372

Why it fits: Removes 12+ contaminants including PFAS and fluoride
Tankless design saves under-sink space
Smart TDS monitoring panel shows real-time water quality
Trade-offs: Professional installation recommended — plumbing required
Higher upfront cost than any jug or tap filter

Typical price

£550approx.

Check current price at Waterdrop

Affiliate link: we may earn a commission at no extra cost to you.

Frizzlife PD600 Under Sink RO

Reverse Osmosis · NSF/ANSI 58

Why it fits: Lower price than Waterdrop G3P600 with similar performance
Twist-and-lock filter replacement — no tools needed
600 GPD flow rate fills a glass in seconds
Trade-offs: Lacks the smart TDS monitoring panel
Slightly noisier pump than Waterdrop

Typical price

£329approx.

Check current price on Amazon

Affiliate link: we may earn a commission at no extra cost to you.

Osmio Fusion 2.0 Installed RO

Reverse Osmosis

Why it fits: Bioceramic remineralisation stage puts minerals back and lifts pH, which flat RO water lacks
Widest contaminant list here, covering fluoride and nitrates as well as chlorine and lead
UK company with UK-based support and spares
Trade-offs: No NSF or WRAS certification stated, unlike the Waterdrop G3P600
Filters need replacing every 6 months at around £126/year

Typical price

£495approx.

Check current price at Osmio

Affiliate link: we may earn a commission at no extra cost to you.

Osmio Fusion 3.0 Installed Hydrogen RO

Reverse Osmosis

Why it fits: Direct feed without a storage tank, so there is no waiting for the tank to refill
Adds a hydrogen generator and chilled water in the same unit
Same broad contaminant coverage as the Fusion 2.0
Trade-offs: £155 more than the Fusion 2.0 for features unrelated to filtration quality
Manufacturer warranty is only 12 months, shorter than most systems here

Typical price

£650approx.

Check current price at Osmio

Affiliate link: we may earn a commission at no extra cost to you.

Osmio Zero 2.0 Countertop RO

Reverse Osmosis

Why it fits: Plugs into a socket — the only RO here that needs no plumbing, so renters can use it
Wastes 1 litre for every 5 produced, far less than a typical under-sink RO
Dispenses at drinking temperature through to near-boiling, so it replaces the kettle too
Trade-offs: No NSF or WRAS certification stated
Osmio does not publish a filter replacement interval, so annual running cost is unclear

Typical price

£495approx.

Check current price at Osmio

Affiliate link: we may earn a commission at no extra cost to you.

Side-by-side comparison

Filter	Price	Rating	Annual Cost
Waterdrop G3P600 Reverse Osmosis (opens in new tab) Maximum contaminant removal including PFAS and fluoride	£550	4.6	£80/yr
Frizzlife PD600 Under Sink RO (opens in new tab) Best value reverse osmosis for UK kitchens	£329	4.5	£70/yr
Osmio Fusion 2.0 Installed RO (opens in new tab) Households wanting remineralised RO water from a UK supplier	£495	4.3	£126/yr
Osmio Fusion 3.0 Installed Hydrogen RO (opens in new tab) Buyers who specifically want tankless RO with hydrogen and chilled water	£650	4.1	—
Osmio Zero 2.0 Countertop RO (opens in new tab) Renters and anyone who wants RO water without a plumber	£495	4.4	£130/yr

Common questions

Does reverse osmosis waste a lot of water?: Modern tankless RO systems like the Waterdrop G3P600 have a 3:1 pure-to-waste ratio, meaning 3 litres of clean water for every 1 litre wasted. Older systems can be less efficient.
Does reverse osmosis remove minerals I need?: RO removes most dissolved minerals. Some systems add minerals back with a remineralisation stage. For most people, a balanced diet provides enough minerals without relying on tap water.

We may earn a commission when you buy through our links, at no extra cost to you. Recommendations are based on water quality data, not sponsorship. Affiliate disclosure