Waterdrop G5P700A Alkaline Mineral pH+ Reverse Osmosis Water Filter, 700GPD review
Hard-water households who want compact, tankless under-sink filtration and don't mind the plumbed install.
By Tom Calder · Price last checked 20 September 2026 · price indicative
A capable tankless RO system: the 2:1 pure-to-drain ratio wastes far less water than older RO designs, and the post-filter mineral stage puts back the calcium and magnesium that plain RO strips out, so it doesn't taste flat. It's a considered, plumbed-in purchase rather than an impulse buy — budget for annual filter changes on top of the unit price. One caveat worth weighing: it's mains-powered with no storage tank, so a power cut means no filtered water at all — pair it with a gravity-fed or manual filter if outage resilience matters to you.
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- 2:1 pure-to-drain ratio is genuinely efficient — far less wasted water than typical RO systems
- Tankless design saves cupboard space and avoids the stale-water taste of stored-tank RO
- 8-stage filtration with alkaline remineralisation gives better-tasting, less flat water than plain RO
- Waterdrop doesn't state WRAS approval for this model — get a plumber to confirm suitable backflow protection under the Water Supply (Water Fittings) Regulations before installing
- Ongoing cost: pre-filters every ~6 months and the RO membrane every ~2 years, roughly £60–£80/year on top of the unit price
Who shouldn't buy this
Skip this if you just want fresher-tasting tap water without a plumbing job — UK tap water is safe to drink, and a basic carbon jug or tap-mounted filter fixes taste, chlorine and scale complaints for a fraction of the price and hassle of a plumbed RO install.
Key specs
| Filter technology | 8-stage reverse osmosis plus a post-RO alkaline |
| Filter life | CF pre-filter ~6 months, RO membrane ~24 months |
| Flow rate | 700 GPD rated output |
| Installation | Tankless under-sink unit, DIY-fit |
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Alternatives to consider
as of 20 Sep 2026, 12:29 BST · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.as of 20 Sep 2026, 12:29 BST · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.as of 20 Sep 2026, 12:29 BST · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.Want this cheaper?
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