Quick verdict: G2P600 is the better value. G3P600 is the better system. Which one you need depends entirely on your budget and how much you care about seeing your water quality data in real time. Both drop London’s 320 ppm TDS down to around 12 ppm — the difference is everything around that core function.
London tap water is treated by Thames Water with chloramine rather than plain chlorine, which leaves a distinct chemical taste. Add 320 ppm of dissolved calcium and magnesium from chalk geology, the possibility of lead in any property built before 1970, and PFAS compounds now under UK Government review in 2026 — and a reverse osmosis system stops being a luxury and starts making practical sense. Both models handle all of this. The question is which one handles it better for your specific situation.
Quick verdict — G2P600 vs G3P600 at a glance
| G2P600 | G3P600 | |
|---|---|---|
| Price installed | £649 | £1,049–£1,199 |
| Filtration stages | 7 | 8 |
| Faucet | Basic stainless steel | Smart digital (TDS display + filter life) |
| Smart features | None | TDS reading, filter life %, holiday mode |
| Filters to replace | 2 | 3 |
| Filter replacement | CF: 12 months / RO: 24 months | All 3: every 12 months |
| Certifications | NSF/ANSI 58, 372 | NSF/ANSI 42, 58, 372 |
| Best for | Flats, renters, budget buyers | Families, homeowners, tech-conscious |
What makes London water different
London tap water sits at 320 ppm TDS — well above the WHO recommended limit of 300 ppm and among the highest of any major UK city. Thames Water uses chloramine (a mix of chlorine and ammonia) for disinfection, which is stable and safe but leaves a stronger chemical taste than standard chlorine. Properties built before 1970 — common across Brixton, Hackney, Islington, and most of inner London — may still have original lead service pipes. Both the G2P600 and G3P600 reduce dissolved lead by 99%+ and bring TDS down to approximately 12 ppm. For PFAS removal, reverse osmosis is currently the most effective domestic method available — something the UK Government acknowledged in its 2026 PFAS Plan.
Waterdrop G2P600 — what you actually get
The G2P600 is a 7-stage tankless RO system with a straightforward 2-filter setup. The G2CF pre-filter handles sediment, rust, and chloramine, and needs replacing every 12 months. The G2MRO reverse osmosis membrane does the heavy lifting — removing dissolved solids, lead, fluoride, PFAS, nitrates, and heavy metals — and lasts up to 24 months. That’s it. Two filters, simple maintenance, no tech to learn.
Flow rate is 600 GPD / 0.42 GPM — roughly a 6oz glass every 4 seconds. The faucet is a clean stainless steel design with no screen or display. Water pressure needs to be between 15–85 psi, which covers the vast majority of London properties.
Pros: Lower price, simpler maintenance, 99.9% bacteria removal, 24-month RO membrane life, compact fit under most London kitchen sinks.
Cons: No water quality display, no filter life monitoring, one fewer certification than G3P600, basic faucet only.
Waterdrop G3P600 — what you actually get
The G3P600 runs the same core RO process as the G2P600 but adds an extra stage — a coconut carbon block (G3-N3CB) that polishes the water after the membrane for noticeably improved taste. It also ships with a smart faucet that shows real-time TDS readings, remaining filter life as a percentage, and a holiday mode that pauses dispensing when you’re away to protect the filters.
Three filters all need replacing every 12 months rather than the G2P600’s staggered schedule — slightly more frequent but easier to remember. The G3P600 carries three NSF certifications (42, 58, and 372) versus the G2P600’s two, which matters if third-party verification is important to you. The pump runs at a slightly higher frequency during dispensing — not loud, but noticeable if your kitchen is quiet.
Pros: Smart faucet with TDS display and filter life monitoring, extra coconut carbon stage for better taste, three NSF certifications, holiday mode, better long-term reassurance.
Cons: Higher price, three filters all on 12-month cycles, slightly louder pump, heavier unit.
Running costs — real numbers
G2P600 annual filter cost: One G2CF pre-filter per year plus one G2MRO membrane every two years. Approximate annual average: £80–£110 per year depending on water usage.
G3P600 annual filter cost: Three filters all replaced every 12 months. Approximate annual cost: £120–£150 per year.
The difference is roughly £40–£50 per year. Over five years that adds up to £200–£250 in extra running costs on top of the higher purchase price. Both systems are tankless so there are no pump electricity costs to factor in. Neither requires a professional visit for filter changes — front-access cartridges on both models.
Which is right for your London home
Renting a flat in London: G2P600. Lower upfront cost, simpler setup, easy to take with you when you move. The basic faucet is perfectly functional and you don’t need smart features for a rental.
Family home with young children or babies: G3P600. The extra coconut carbon stage improves taste noticeably, the smart faucet confirms water quality at a glance, and three NSF certifications give more documented reassurance for drinking water safety.
Homeowner who wants data and reassurance: G3P600. The real-time TDS display means you can see your water quality every time you use the tap — and the filter life monitoring removes any guesswork about when to replace.
Budget under £700: G2P600. It delivers the same core RO filtration — 320 ppm London water drops to ~12 ppm either way. The smart features of the G3P600 are genuine improvements, but the G2P600’s filtration performance is not compromised by their absence.
Frequently asked questions
Which Waterdrop system is best for London water?
Both reduce London’s 320 ppm TDS to approximately 12 ppm and remove chloramine, lead, PFAS, and fluoride. The G2P600 is the better value choice for most households. The G3P600 is worth the extra cost if you want smart monitoring and improved taste from the extra coconut carbon stage.
Is the G3P600 worth the extra money?
Yes, for homeowners and families who want real-time water quality data and a better tasting result. No, for renters or budget-conscious buyers — the core filtration performance is the same and the G2P600’s running costs are lower.
Does Waterdrop remove limescale from London water?
Both systems remove the dissolved calcium and magnesium that cause limescale in drinking water, dropping TDS from 320 ppm to around 12 ppm. They treat drinking water only — not the rest of your home’s water supply. For whole-property limescale protection, a water softener or whole house filter is the better solution.
Can I install a Waterdrop system in a London flat?
Yes. Both models are compact tankless designs built for under-sink installation. They fit under most standard London kitchen cabinets. London Water Filter installs both across all London boroughs, including flats and apartments, usually within the same week.
How often do Waterdrop filters need replacing?
G2P600: pre-filter every 12 months, RO membrane every 24 months. G3P600: all three filters every 12 months. Actual frequency depends on water usage and local water quality — London’s higher TDS may shorten membrane life slightly compared to softer water areas.
Ready to get either system installed in your London home?
London Water Filter is a Waterdrop authorised dealer based in SW2, covering all London boroughs with same-week installation by our own engineers — no subcontractors. We TDS-test your water before and after and give you a written report. Book a free water test at londonwaterfilter.co.uk/test-water-quality/ and we’ll recommend the right system for your property.
