Reverse osmosis in Barcelona, installed and maintained
Say goodbye to tap water worries & bad taste.
What a home reverse osmosis system does
Reverse osmosis pushes tap water through a membrane with pores of about 0.0001 microns. Water molecules pass; most dissolved salts, metals and other contaminants stay behind. At home it sits under the kitchen sink and feeds its own tap next to your usual one.
The Oasly system filters in 7 stages across 3 cartridges: a sediment and carbon pre-filter, the reverse osmosis membrane, and a remineralisation filter that adds calcium, magnesium and potassium back. Without that last step RO water tastes flat; with it, the water ends up slightly alkaline and tastes like water.
Heavy metals
Lead 99.8%, arsenic 99.9%, chromium VI 99.6%
Tested to NSF/ANSI 58-2023
PFAS
PFOS 99.6%, PFOA 99.4%
Tested to NSF/ANSI 58-2023
Chlorine (taste)
99.5%
Tested to NSF/ANSI 42-2023
Dissolved solids (TDS)
94–95%
Minerals are added back afterwards
Figures from SGS report NBF25-0016876-01, measured with a new membrane; performance drops as filters age. The full technical detail is on the Oasly Home product page.
Tankless (direct-flow) reverse osmosis
Many RO systems store filtered water in an 8–12 litre pressure tank. Oasly does not: it filters the moment you open the tap, with a 600 GPD membrane that fills a 330 ml glass in about 10 seconds.
Space under the sink
Unit plus an 8–12 L tank
One slim unit, 14 cm wide
Water to drain
About 1 part filtered to 3 to drain
2 parts filtered to 1 to drain
Stored water
Sits in the tank between uses
None: filtered on demand
Filter changes
Housing wrench, often a plumber
By hand, and on subscription we do it
Figures for tank systems are typical market values and vary by model.
Reverse osmosis installation in Barcelona
Almost no Barcelona kitchen needs building work. We need about 45 × 45 × 45 cm free under the sink, an earthed 230 V socket, the cold-water shut-off valve and the sink drain pipe, where a clamp goes on without cutting anything.
The standard tap needs a 1.3 cm hole in the worktop. If you rent and would rather not drill, we swap your tap for a 3-way tap (€79.90, yours to keep) that gives normal and filtered water. The visit takes about two hours and is usually booked within 1–5 days. Before we leave we measure your water's TDS before and after the system and show you both numbers.
Not sure it fits? Send us a photo of the cupboard under your sink on WhatsApp and we will confirm before booking.
Reverse osmosis price: subscription or purchase
Monthly subscription
€24.90/month in Barcelona city (€27.90 in Badalona, L'Hospitalet, Sant Cugat and Esplugues)
System, installation, yearly filter change, maintenance, and a free move within the service area
Yearly subscription
€249/year (€279 in the wider area)
The same, paid once: almost €50 a year less in Barcelona city
Purchase
€629 for the system, or €699 installed in Barcelona
You own it, with the 3-year legal guarantee; filters and maintenance are on you
Subscriptions have no minimum term and no deposit: cancel any time with two months' written notice.
Changing reverse osmosis filters
The pre-filter and remineralisation filter are changed every 12 months, the membrane every 24, assuming typical Barcelona mains water and normal household use. The cartridges twist off by hand, no tools.
On subscription there is nothing to remember: we track every filter, message you when one is due and come and change it at no extra cost. If you buy the system, you buy the filters.
Where we install
Barcelona city (postcodes 08001–08042), Badalona, L'Hospitalet de Llobregat, Sant Cugat del Vallès and Esplugues de Llobregat. We can often reach nearby areas too: send us your postcode. To see what your local water is like, check the official hardness data by supply zone.
Live in a rented apartment? No problem.
We seal the hole
Upgrade to a 3-way faucet
No extra hole needed
How does it work
Sign up via WhatsApp
Installation included
Enjoy unlimited water
Yearly filter swap
We move with you
Oasly vs. carbon filter jugs
How much do you really spend on bottled water?
How does the filtration work?
Feedback from people who switched to Oasly
Reverse osmosis in Barcelona: common questions
How much does reverse osmosis installation cost in Barcelona?
With Oasly installation is included in the subscription: €24.90/month or €249/year in Barcelona city, with nothing to pay upfront. If you would rather buy the system, it costs €699 installed in Barcelona or €629 for the system alone.
Is reverse osmosis worth it in Barcelona?
Barcelona tap water is safe to drink. Reverse osmosis makes the difference on chlorine taste, limescale (most of the city has hard water) and reducing contaminants such as lead or PFAS. If the taste only bothers you a little, a carbon filter may be enough.
Does reverse osmosis remove minerals?
The membrane reduces dissolved solids by 94–95%, minerals included. That is why Oasly's last cartridge adds calcium, magnesium and potassium back and leaves the water slightly alkaline.
How much water does an RO system waste?
The Oasly system runs at 2:1: for every 2 parts of filtered water, 1 goes to drain. That is about 6 times less water to drain than a conventional 1:3 system.
How often are the filters changed?
Pre-filter and remineralisation every 12 months, membrane every 24. On subscription we change them and let you know beforehand.
Can I install reverse osmosis in a rented flat?
Yes. We can fit a 3-way tap that replaces yours without drilling the worktop, or cover the tap hole neatly when you move out. If you move within our area, we reinstall the system for free.
Is there a minimum term?
No. Cancel any time with two months' written notice, with no deposit and no upfront cost.
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