iSpring RCC7AK-UV review
iSpring RCC7AK-UV 7-Stage Under Sink Reverse Osmosis Drinking Water Filtration System
By Tom Calder
Key specs
The maker's figures.
- Filter technology
- 7-stage RO + UV sterilisation + alkaline
- Filter life
- F10KU set ~12 months
- Flow rate
- 75 GPD rated output under ideal test conditions
- Installation
- Under-sink
A well-specified 7-stage system from an established brand, adding UV sterilisation and partial alkaline remineralisation on top of standard RO — genuinely useful if you're on a private supply or want extra reassurance beyond taste and scale. It's a serious outlay next to a jug or tap filter, and it's a proper install (drilled faucet hole, cold feed, drain saddle), so it suits people wanting a permanent fix rather than a stopgap. Check your mains pressure before ordering — this unit doesn't include a booster pump, and plenty of UK kitchens run below what it needs.
- Best for
- Homes on mains or private supply wanting a permanent, comprehensive under-sink RO setup with UV backup, prepared to do a proper plumbed-in install.
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Researched, not used. We haven't used this product. This review is built from the maker's specifications, owner reports and our own sizing.
What we like
- Adds UV sterilisation and alkaline remineralisation stages many rivals in this price band skip
- Long-established brand with a solid UK sales track record and NSF/ANSI 58-tested RO performance
- F10KU bundle option covers a full year of pre/post-filter replacements out of the box
Worth knowing
- No permeate pump, so the waste-water ratio runs around 1:3 — thirstier than pump-assisted systems
- NSF/ANSI 58 certified (the US standard) rather than WRAS-approved — not a legal requirement, but worth checking against the Water Supply (Water Fittings) Regulations if that matters to you
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Our review
A conventional tanked reverse-osmosis system from an American maker, with two stages added after the membrane: a remineralising cartridge and an 11-watt ultraviolet lamp. For a UK kitchen the number that matters most is not the 75 gallons a day but the 45 psi minimum feed pressure, which many British homes cannot promise without a booster pump. It suits households on a private supply, or with a specific contaminant concern, who have measured their pressure first.
What it is, stage by stage
Water goes through a sediment filter, two carbon stages (granular, then a carbon block), the reverse-osmosis membrane, a post-carbon polish, the alkaline cartridge (iSpring part FA15) and finally the UV chamber. The membrane is rated at 75 US gallons a day, about 284 litres, under iSpring's test conditions; a pressurised tank of nominally 3.2 gallons (around 12 litres) stores the output. The unit is 15.5 by 5.1 by 19 inches, roughly 39 by 13 by 48 cm, plus the tank, and weighs about 9 kg.
The system is certified to NSF/ANSI 58 (certificate C0536866, NSF International, 2022). The published reductions include total dissolved solids 97.9%, lead 98.9%, fluoride 97.4%, chromium 99.2% and asbestos above 99.7%. iSpring's FAQ says the mineral cartridge typically lifts pH by 0.5 to 0.8 depending on the source water.
Pressure: the UK problem
iSpring specifies 45 to 70 psi (3.1 to 4.8 bar) at the inlet, feed water of 4 to 38°C and up to 750 ppm dissolved solids. Its manual says a booster pump is needed below 45 psi and its APR70 regulator above 70; the product FAQ concedes it may run at 35 psi, but not efficiently. For context, the legal minimum water companies must maintain at the pipe serving your home, under Ofwat's guaranteed standards scheme, is seven metres head, about 0.7 bar or 10 psi; plenty of homes see far more, but measure at the kitchen stop tap before ordering.
Without a pump this is a pressure-fed system, and it is thirsty. iSpring's own FAQ puts the ratio with the tank at 1:3, so three litres go to the drain for each litre kept (its spec table says up to 1:2; take the worse figure). Expect the tank to take one to two hours to fill from empty, and discard the first tankful.
In a power cut
The reverse-osmosis side runs on water pressure, not electricity, and the tank keeps dispensing, so in an outage you still get filtered water. Only the UV lamp and its ballast need the mains; a flow sensor switches the 11-watt lamp on when water moves, and in a power cut it simply stays dark. One UK detail: iSpring makes 110-volt and 220-volt versions of the UV ballast, so check which ships with a UK listing; you will need a socket under the sink.
How it compares
Both Waterdrop units we review solve the pressure problem with a built-in pump. The Waterdrop G3P600 is rated from 14.5 psi, makes up to 600 gallons a day without a tank and sends one litre to drain for every two kept; the Waterdrop G5P700A adds a mineral stage like the iSpring's. Neither has UV or a tank, and both stop in a power cut. The iSpring is the choice only when you specifically want UV and stored water, and have the pressure to drive it.
Living with it
iSpring sells replacement packs for this model as F10KU, F21KU75 and F31KU75 (10, 21 and 31 pieces), with the UV bulb (part UVB11) also sold on its own. The warranty is one year, with a one-year money-back guarantee and lifetime technical support from iSpring's team in Atlanta, Georgia. A brass faucet is included and wants a half-inch hole, though its base covers an existing hole up to two inches. iSpring asks you to check for leaks daily for the first fortnight, and includes a mechanical leak-stop valve. iSpring does not state WRAS approval, so fit it with the backflow protection the Water Fittings Regulations require, ideally via a WaterSafe plumber.
Our verdict
Buy it if you are on a private supply or have a documented contaminant problem, want both a stored reserve and a UV stage, and have confirmed at least 45 psi at the sink. Otherwise a pumped tankless unit gives you RO water from any normal UK pressure with a third of the waste, and for mains water that is already safe (see is UK tap water safe) a carbon filter may be all you need.
A researched review, built from the maker's specs, manual and UK listings; facts checked 21 Oct 2026. Sources: iSpring RCC7AK-UV product page (iSpring Water Systems); iSpring RCC series installation and operation manual (PDF); Ofwat: water pressure and the guaranteed standards scheme.
Who shouldn't buy this
Don't buy this without checking your mains pressure first — it needs 45–70 psi (3.1–4.8 bar) and doesn't include a booster pump, and a lot of UK kitchens run below that, risking poor output or premature membrane fouling (iSpring sells a separate booster, the RCC1UP-AK, if you need one). It's also not the right buy if your only concern is general mains-water taste with no particular hardness, lead-pipe or private-supply worry — a jug or tap-mounted filter does that job for a fraction of the cost and no plumbing work.
This is a Researched review: we haven't used this product. We check every specification against at least two independent sources, re-check the UK price on a schedule where we can track it automatically, and say plainly who it isn't for. Commissions never change a rating.
If this isn’t the one
Best for Renters and homeowners who want better-tasting, chlorine-free tap water fast, without drilling a tap hole or fitting a drain line.
as of 4 Nov 2026, 19:07 GMT · 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.
Best for Hard-water households who want a compact, tankless under-sink RO system with alkaline remineralisation and have a spot with mains power and a drain nearby.
as of 4 Nov 2026, 19:07 GMT · 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.
Best for Hard-water households who want compact, tankless under-sink filtration and don't mind the plumbed install.
as of 4 Nov 2026, 19:07 GMT · 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.Questions
What water pressure does the iSpring RCC7AK-UV need?
iSpring specifies 45 to 70 psi (3.1 to 4.8 bar). Below 45 it says a booster pump is needed; above 70, its APR70 pressure regulator. It may produce water at 35 psi, but slowly and with more waste.
Does the iSpring RCC7AK-UV work in a power cut?
Mostly. Filtration and the storage tank run on water pressure, so the tap still works. The UV lamp needs mains power and goes dark until the supply returns.
How much water does the iSpring RCC7AK-UV send to the drain?
iSpring's FAQ gives a 1:3 ratio with the tank, three litres to drain per litre kept; its spec table claims up to 1:2. Low pressure and cold feed water make it worse.
Is the iSpring RCC7AK-UV WRAS approved?
iSpring does not state WRAS approval; it is certified to the US standard NSF/ANSI 58. UK plumbing rules still apply, so it needs an isolation valve and backflow protection on the cold feed; a WaterSafe-registered plumber can confirm compliance.
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