Limitless Hydration

Oasly uses a 600 GPD (gallons per day) tankless reverse osmosis (RO) system with alkaline remineralization. Unlike traditional RO systems with bulky storage tanks, the tankless design is compact, avoids stored water, and delivers fresh filtered water on demand. It takes about 10 seconds to fill a 330 ml glass and is rated at 600 GPD, up to 2,270 litres a day.

Reverse osmosis uses a semi-permeable membrane to remove ions, unwanted molecules and larger particles from drinking water. The Oasly system pushes tap water through a membrane with pores of about 0.0001 micron: small enough to reject dissolved salts, metals and most other contaminants while water molecules pass through.

In independent SGS report NBF25-0016876-01, testing to NSF/ANSI 58-2023 measured reductions of 94–95% for total dissolved solids, 99.8% for lead and 99.9% for arsenic. Rates were measured at startup with a new membrane; real-world performance declines as filters age.

Seven stages across three cartridges:

• Stages 1–2, composite pre-filter: a PP sediment layer for sand, silt and rust, then an activated carbon block for chlorine, taste and odour.
• Stages 3–5, reverse osmosis: a pre-RO layer, the 600 GPD membrane (94–95% TDS reduction, plus heavy metals, PFAS and nitrates) and a post-RO flow regulator.
• Stages 6–7, remineralization filter: alkaline media that leave the water slightly alkaline, then a mineral and carbon block that adds calcium, magnesium and potassium and polishes the taste.

It is a 3-in-1 filter that solves the main drawbacks of plain reverse osmosis:

• Alkaline particles: water straight off an RO membrane is slightly acidic; this stage leaves it slightly alkaline.
• Mineral restoration: RO strips the minerals that give water its taste. This stage adds calcium, magnesium and potassium back, so the water doesn't taste flat.
• Carbon polish: a final carbon layer removes any residual taste or odour.

Because minerals are added back, a TDS pen reads slightly higher after remineralization than straight off the membrane. That increase is the minerals, not contaminants.

TDS stands for total dissolved solids: everything dissolved in the water, measured in ppm or mg/L. The RO membrane reduces TDS by 94–95% on incoming mains water. The remineralization stage then adds calcium, magnesium and potassium back, so the finished water reads slightly higher than water straight off the membrane.

That small increase is intentional. We measure your TDS before and after installation and show you both numbers.

Traditional RO systems store filtered water in a pressurised tank. The water sits there between uses, the tank takes up space under the sink, stored water can taste stale, and tanks eventually need replacing.

The Oasly tankless design filters every drop the moment you open the tap: nothing is stored, it takes less space, and there is no tank to clean or replace.

The drain ratio is how much water goes to the drain during filtration compared with the filtered water produced. Traditional RO systems often run at 4:1 or worse. Oasly runs at 2:1, which sends roughly 6× less water to the drain than a conventional 1:3 system.

About 10 seconds to fill a 330 ml glass. The system is rated at 600 GPD, up to 2,270 litres a day: enough for a large household. The internal pump and direct-flow design make it faster than most tank systems.

Figures from independent SGS report NBF25-0016876-01 (NSF/ANSI 58-2023 unless stated):

• Heavy metals: lead 99.8%, arsenic 99.9%, mercury 97.1%, chromium VI 99.6%, cadmium 99.6%, copper 99.3%.
• PFAS (“forever chemicals”): PFOS 99.6%, PFOA 99.4%.
• Chlorine 99.5% (tested to NSF/ANSI 42-2023). Chloramine and trihalomethanes are also reduced but were not part of the SGS panel.
• Microplastics, parasitic cysts (Giardia, Cryptosporidium), pesticides, pharmaceutical residues, VOCs, sediment and rust.
• Nitrates 96.8%, fluoride 94.7%.

Rates were measured at startup with a new membrane; real-world performance declines as filters age.

Yes. Microplastics are typically 1–5,000 microns; the RO membrane pores are about 0.0001 micron, so microplastics are far too large to pass and are retained. Microplastics were not part of the SGS test panel, so we don't quote a reduction figure for them.

Barcelona tap water meets EU drinking-water standards and is safe to drink. People filter it for other reasons:

• Taste and hardness: the water is hard, which gives it a distinct taste and leaves limescale.
• Chlorine used for disinfection affects smell and taste.
• Convenience: unlimited drinking water at the tap, with no bottles to buy, carry or store.

We don't claim your tap water is unsafe. If you like how it tastes, you may not need us.

The difference is architecture. Bottled or delivered water is treated elsewhere, stored in plastic and transported to you, so it can run out and needs floor space. Water filtered at the tap comes from your own mains and is filtered the moment you open the tap, with nothing stored.

On cost, our prices are published: €24.90 a month, €249 a year, or €629–€699 to buy the unit outright, with unlimited water.

After several hours without use, the first water can read higher for 30–60 seconds. This is “osmotic creep”, normal in every RO system: when the pump stops, a small amount of dissolved solids migrates across the membrane. The reading settles within about a minute of continuous flow. It's normal physics, not a defect.

A handheld TDS pen measures the water after all seven stages, including remineralization. That stage adds calcium, magnesium and potassium back for taste, so the finished water reads higher than water straight off the membrane. The difference is the minerals, not contaminants. It's not the same figure as the 94–95% reduction we quote, which describes what the membrane removes from incoming mains water.

• A 230 V power outlet under or near the sink.
• A cold-water supply line (standard kitchen connection).
• Under-sink space of at least 45 × 45 × 45 cm.
• A drain connection for waste water.

Faucet options: the standard filtered-water faucet needs a ~1.3 cm (13 mm) hole in the worktop or sink. The 3-way faucet upgrade (€79.90) replaces your existing tap and delivers both filtered and regular water, with no extra drilling.

Most Barcelona kitchens have one, often used for the dishwasher. If it's taken, we bring a double adapter so both appliances can connect, or an extension can reach an outlet in a nearby cabinet. If there's truly no accessible outlet, an electrician would need to install one (not included); we can recommend one.

For the standard faucet, yes: a small hole of about 1.3 cm, in a spot we choose with you, usually near the existing tap. If you'd rather not drill, we seal the hole with a matching cover plate when the service ends, or you can choose the 3-way faucet (€79.90), which replaces your existing tap and is yours to keep.

The standard mounting hardware fits worktops up to about 3.8 cm. For thicker granite or composite worktops, email support@oasly.es and we'll supply an extended threaded shaft at no extra charge.

Usually 45–90 minutes. The technician checks the site, connects the water supply and drain, installs the faucet, powers on and tests the system, runs the initial flush (15–30 minutes), shows you how it works and checks the TDS reading.

With the “machine only” purchase (€629, installation not included), yes. You get a detailed manual, video tutorials and WhatsApp support. You'll need basic plumbing confidence, a drill with a 13 mm bit for the faucet (unless you use the 3-way option) and an adjustable wrench. If you're not confident with plumbing, we recommend the €699 option with installation in Barcelona.

Many renters use Oasly. The installation involves a small hole or a 3-way faucet swap, plus reversible connections to the water supply and drain. Options for renters: the 3-way faucet (we reinstall your original tap when you leave), the standard faucet with a cover plate when service ends, or written approval from your landlord. If you move within Barcelona, we relocate the system free as part of your subscription.

• The Oasly RO unit (remains Oasly property) and remineralization filter.
• Professional installation and the standard filtered-water faucet.
• All maintenance and service calls, and the yearly filter change (we come to you).
• Free relocation if you move within the service area.
• No deposit and no upfront cost.

Barcelona city (08001–08042): €24.90/month or €249/year. Esplugues, Badalona, L'Hospitalet de Llobregat and Sant Cugat del Vallès: €27.90/month or €279/year. Same service in both areas. No minimum term: cancel at any time with two months' written notice.

No. There is no deposit and no upfront cost on any plan.

• Within 14 days of installation: the EU withdrawal period applies and you get a full refund.
• Notice period: two months' written notice; the subscription stays active during that time.
• Within the first 12 months: a one-off €75 early-termination amount may apply to cover the installation cost. It isn't a deposit and doesn't apply during the withdrawal period, if we're at fault, or if the unit is defective.
• After 12 months: no cancellation fee, and removal is free.

We arrange collection of the unit at a time that suits you.

Yes, message us on WhatsApp. Monthly to yearly: you pay the yearly rate and monthly payments stop. Yearly to monthly: monthly billing starts when the current year ends.

Subscription: no deposit or upfront cost; installation, all filters, maintenance and service calls included; free relocation within the service area; the unit belongs to Oasly; no minimum term.

Purchase (€629 machine only, self-installed, or €699 installed in Barcelona): you own the unit, buy replacement filters yourself (roughly €30–€100 each), handle maintenance or pay for service visits, and get the 3-year EU statutory conformity warranty. Ships across mainland Spain and the Balearic Islands.

Yes. Consumption varies a lot between businesses and can mean more frequent filter changes, so we quote individually based on daily consumption, number of users and how many units you need.

For purchase customers (subscribers get all filters included):

• Composite pre-filter: every 12 months, about €35–€40.
• Reverse osmosis membrane: every 24 months, about €90–€100.
• Remineralization filter: every 12 months, about €40–€45.

That's roughly €75–€85 a year, plus €90–€100 every second year for the membrane.

• Composite pre-filter: every 12 months (sediment, chlorine).
• RO membrane: every 24 months (the deep purification).
• Remineralization filter: every 12 months (minerals and taste).

Subscribers don't need to track anything: we schedule the changes. Purchase customers order replacements on these intervals from the installation date. Heavy use or poorer incoming water can shorten the lifespan.

No tools needed. For the first two cartridges: switch off power and water, twist the filter anticlockwise to remove it, twist the new one in clockwise until it locks, restore water and power, and run the water for 15 minutes before drinking. The remineralization filter has a built-in shut-off valve: just twist the old one out, the new one in, and flush for 2–3 minutes. Video tutorials are available on request.

Subscribers: WhatsApp us on +34 699 977 079. We diagnose remotely where possible, schedule a free service visit if needed, and replace the unit if it can't be repaired.

Purchase customers: WhatsApp support for troubleshooting; the 3-year EU statutory conformity warranty covers defects; service visits after that are charged separately.

It's air. The pump pressurises the water, air dissolves under pressure, and it forms tiny bubbles when the pressure is released. Let the glass stand for 30–60 seconds and they disappear. The water is fine to drink straight away.

• An overdue pre-filter restricts flow: replace it.
• Low mains pressure: the system needs at least 1.4 bar; check your other taps.
• Kinked or crushed tubing under the sink.
• An overdue membrane (after 24 months) loses efficiency.
• Very cold incoming water slows the membrane slightly.

Subscribers: message us on WhatsApp and we'll sort it.

Yes. It reduces limescale in coffee machines, kettles, humidifiers and steam irons. Most plants and freshwater aquariums do well with remineralized RO water, and it's fine for pets.

In Barcelona city (all districts, postal codes 08001–08042) and in the extended area of Esplugues, Badalona, L'Hospitalet de Llobregat and Sant Cugat del Vallès. Not sure about your address? Send us your postal code on WhatsApp and we'll confirm.

Yes. The “machine only” option (€629, self-installed) ships by courier across mainland Spain and the Balearic Islands, with WhatsApp support for installation questions. Replacement filters are available from oasly.shop.

Subscribers: relocation within the service area is free. Send us your move date and new address on WhatsApp; we collect the unit and reinstall it at your new home. Purchase customers can move it themselves or use a plumber; we can recommend one.

Usually within 3–7 days of signing up. Morning slots 9:00–13:00, afternoon slots 15:00–19:00, and some Saturdays. Ask on WhatsApp if it's urgent.

Water straight off an RO membrane tastes flat because the minerals are gone. The final stage adds calcium, magnesium and potassium back, so it tastes like water and comes out slightly alkaline. The minerals are there for taste; we don't present the water as a nutritional supplement.

The water is filtered by reverse osmosis, remineralized with calcium, magnesium and potassium, and can be boiled as normal. Always follow the formula manufacturer's instructions and your paediatrician's advice on preparing bottles; many recommend boiling water even when it's filtered. We don't make health claims about our water for infants.

Yes. Dogs, cats and other pets can drink it, and remineralization means it isn't mineral-free water. For sensitive aquarium species or saltwater tanks, ask us about options.

Yes: rice, pasta, soups, stocks and sauces, with no chlorine taste and less limescale in pans and kettles.

No plastic bottles to make, deliver or throw away, and no delivery trucks. The 2:1 drain ratio sends far less water to the drain than older RO systems, and the pump uses about 85 W, only while producing water.

It's just more concentrated tap water: the dissolved solids that didn't pass the membrane. It goes into your sink drain with normal household waste water. Some customers collect it for watering ornamental plants or cleaning floors.

Filter housings are often recyclable (check local rules) and the unit contains recyclable plastics and metals. For subscribers we handle the equipment when service ends; purchasers can use an e-waste point.

A jug uses activated carbon only, which improves taste and odour. Oasly uses carbon plus a reverse osmosis membrane with 0.0001 micron pores, then remineralizes the water. It's unlimited on demand (no refilling a 2–3 litre jug), filters are changed yearly instead of every 1–2 months, and we measure your TDS before and after installation.

Oasly filters your own mains water at the tap, stores nothing, creates no plastic waste and can't run out. Bottled water is treated at a plant, sits in plastic until you drink it, has to be bought, carried and stored, and runs out. Oasly costs €24.90 a month, €249 a year, or €629–€699 to buy.

Published prices with no hidden fees, tankless equipment, WhatsApp-first support, monthly, yearly or purchase options, free relocation within the service area, and a TDS reading before and after installation.

That's osmotic creep: when the system rests, some dissolved solids migrate across the membrane. The first 10–30 seconds can read higher, then it settles. The water is fine to drink straight away.

Yes, while dispensing: the pump hums gently. Grinding, clicking, loud vibration or any sound with the tap closed isn't normal; message us.

Check that all filters are fully seated and twisted clockwise, that the tubes are pushed firmly into their fittings, that the drain tube is secure, and that no housing is cracked. If it keeps leaking, close the water supply and contact us straight away.

Normal with new filters. Run the water for 15–20 minutes after changing the first two cartridges, and 2–3 minutes after the remineralization filter. If the taste persists after flushing, contact us.

OASLY AQUA, S.L. is a water filtration company based in Barcelona (CIF B22655765, Carrer del Degà Bahí 28, 08026 Barcelona). WhatsApp +34 699 977 079, email support@oasly.es.

A tankless, direct-flow reverse osmosis unit with seven filtration stages across three cartridges, configured for Barcelona water and European electrical standards (230 V/50 Hz).

• WhatsApp (fastest): +34 699 977 079
• Email: support@oasly.es
• Legal: legal@oasly.com
• Privacy and data requests: privacy@oasly.com

Online at oasly.shop, or send us your postal code on WhatsApp (+34 699 977 079) and we'll take it from there.