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Frequently Asked Questions
This nanobubble FAQ collects the questions buyers actually put to NanoSWIM before they sign anything: what nanobubbles are, whether a pool can genuinely run without chlorine, what an installation involves, what it costs to operate, and what the Norwegian regulations expect of a public facility. The answers are short, and they include the cases where this is the wrong technology for you.
Written by the people who install the systems. If your question is not here, ask it — technical questions get technical answers.
Up to 90%
Less chemical use
Measured against conventional chlorine dosing on comparable pools. See our references.
99.9%
Pathogen reduction
Oxidative disinfection in the treatment loop.
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Questions answered
Ordered the way a buying decision actually runs.
The questions below are ordered the way a purchase usually unfolds — from the physics, through the practical questions about installation and running cost, to the regulatory paperwork a municipal buyer will ask for. If you are only here for one thing, use this map:
- Nanobubbles themselves — what they are, and why the size is the whole point. The full explanation lives on nanobubble technology.
- Chlorine-free pool water — what is realistic and what is not. The long-form buyer’s guide is chlorine-free pools.
- Installation and retrofit — what has to be true about your plant room before anything else matters.
- Operation, maintenance and service — what changes in daily operation, and what wears out.
- Cost and payback — how to compare quotes so the numbers actually mean something.
- Regulation and documentation — what a Norwegian public facility has to be able to show. See also standards and compliance.
- Wellboats — oxygen during transport and disinfection of the wells between assignments. The systems are described on wellboat oxygenation and disinfection.
The short version, before the detail
If you want the answer to what are nanobubbles in one paragraph: they are gas-filled bubbles under roughly 200 nanometres across, small enough that buoyancy barely acts on them, so they stay suspended in the water instead of rising and bursting. That gives them an enormous combined surface area, which is what lets a system dissolve oxygen or ozone into water far more completely than coarse injection can.
In a swimming pool, the NanoSWIM Pool System uses that to oxidise the organic load that would otherwise turn into chloramines — the compounds actually responsible for the chlorine smell, the stinging eyes and the corroded ventilation ducting. The application detail is on pool water treatment.
And the honest limit, stated once here so it does not have to be repeated in every answer below: this is a treatment-loop technology. It acts on water that passes through the plant room. It is not a chemical you throw in the basin, and it does not replace a correctly sized filter, sensible pH control or competent operation.
Sources and further reading
- Norwegian Institute of Public Health — guidance on bathing water and pool operation (Folkehelseinstituttet, badevannsveileder).
- Regulation on bathing facilities, swimming pools and saunas (forskrift om badeanlegg, bassengbad og badstu), Norwegian Ministry of Health and Care Services.
Nanobubble FAQ: the questions we get asked most
What are nanobubbles?
Nanobubbles are gas-filled bubbles smaller than roughly 200 nanometres — thousands of times smaller than a grain of salt. Because they are so small, buoyancy barely acts on them, so they do not rise and burst; they stay suspended in the water for days. They carry a negative surface charge and an enormous combined surface area, and that surface area is what makes them useful for transferring gas and driving oxidation. The physics is set out in full on nanobubble technology.
How are nanobubbles different from the bubbles I can already see?
Visible bubbles rise to the surface within seconds and release most of their gas into the air above the pool rather than into the water. Nanobubbles are invisible, stay in suspension, and transfer their gas into the water far more completely. That difference in gas transfer is the entire reason the technology exists — it is not a stronger version of aeration or a fancier jacuzzi jet.
Do nanobubbles work in swimming pools?
Yes — a pool is one of the applications the technology fits best, because the circulation loop the system needs is already there. In a pool the bubbles do three jobs: they oxidise the organic load that would otherwise become chloramines, they help lift fine particles and biofilm off surfaces so the filter can remove them, and they improve clarity. What they cannot do is treat water that never reaches the plant room, which is why turnover rate matters more than pool length.
Is nanobubble treatment safe for swimmers?
Yes. What goes into the water is gas — oxygen or ozone — not a chemical that leaves a residue behind for skin or eyes to react to. That is why people with sensitive skin or eczema tend to notice the difference before anyone looks at a test result. Where ozone is used, off-gas handling is part of the system design, because ozone is hazardous to breathe in concentration and must never be allowed to build up in the pool hall.
Can a swimming pool be completely chlorine-free?
A private pool, hotel pool or spa can be. A public pool in Norway usually cannot go to zero, because the bathing-facility regulations effectively require a measurable disinfectant residual in the basin so that contamination introduced by one bather cannot reach another before the water has circulated. What a public facility can realistically achieve is a large reduction — enough that the smell and the eye irritation disappear. The full argument, including the alternatives, is on chlorine-free pools.
Why does my pool smell so strongly of chlorine?
A strong chlorine smell almost always means too little free chlorine relative to the bather load, not too much. The smell comes from chloramines — combined chlorine formed when free chlorine reacts with sweat, urine, cosmetics and skin oils. A well-run pool smells of almost nothing. Removing the organic load before it can become chloramine is precisely what a nanobubble system is for.
Why does pool water turn green or cloudy?
Green normally means algae growing faster than the disinfection regime can keep up with; cloudy normally means fine suspended particles the filter is not catching, or a water-balance problem such as pH drift. Both are symptoms of the same thing — the treatment loop is behind the load. Nanobubbles help with both, by oxidising organic material and by making fine particles easier to filter, but they do not compensate for an undersized filter or for water balance that is left unmanaged.
Does chlorine-free water still need testing?
Yes, and arguably more attentively. pH, water balance and disinfection performance all still have to be measured and logged. Chlorine-free means you are managing a different set of parameters, not fewer of them. For a public facility the logging requirements come from the bathing-facility regulation regardless of which technology is installed.
Will it help swimmers with sensitive skin, eczema or asthma?
It removes the most common trigger, which is combined chlorine in the water and in the air above it. Swimmers, instructors and lifeguards with sensitive skin or irritated airways are usually the first people to comment after a changeover. We are deliberately careful not to make medical claims: what we can say is that the chloramine load blamed for most of those complaints is exactly what the system is designed to prevent from forming.
Does it work with all pool types?
It works with any pool that has a real circulation loop — concrete, liner, tiled, indoor, outdoor, fresh water or salt. What decides feasibility is not the basin but the plant room: flow rate, physical space and power supply. The cases where it does not fit are pools with no proper circulation system, and natural ponds with no plant room at all.
Can I retrofit a nanobubble system to an existing pool?
In most cases yes. The unit installs into the existing circulation loop after filtration, so the basin, the pipework and the filter stay as they are, and the pool does not have to be drained or rebuilt. A retrofit into an existing system is the normal case rather than the exception. What has to be checked first is flow rate, available space in the plant room and the electrical supply.
What do you need to know before you can quote?
Five things: pool volume, turnover rate, indoor or outdoor, your current chemical consumption, and the facility type. With those we can tell you whether a retrofit is straightforward, which unit size fits, and whether the economics work for you. Without them, any figure a supplier gives you — ours included — is a guess. Ask your question and bring whatever numbers you already have.
How long does installation take, and do we have to close the pool?
Installation is plant-room work, so it disrupts far less than anything involving the basin. On duration, the honest answer is that it depends on your pipework, the space you have and the electrical supply — we give a schedule after a site visit, not over the phone. Any supplier who quotes an installation time before seeing your plant room is guessing.
Which system fits a small pool?
Small and mid-size installations are what the NanoSWIM Compact Unit is built for: a plug-and-play install for plant rooms where space is tight. Larger commercial pools and public facilities are matched to the NanoSWIM Pool System or a larger unit instead. Published flow rate and volume figures for each are on the product pages, but the right choice comes from your turnover rate rather than from the size of the basin.
What maintenance does the system need?
Day-to-day it is monitoring rather than manual work: the unit runs with the circulation pump and there is no chemical to order, store, mix or dose. The rest of the plant still needs the same attention it always did — backwashing, pH control and water balance do not go away. We tell you the service interval and what a service visit covers for the specific unit you are quoted, before you order rather than after.
What is the lifetime of the equipment, and what wears out?
Ask this of every supplier you talk to, including us, and get the answer in writing. A nanobubble unit has no consumable equivalent to a UV lamp or a salt cell, which is a real cost advantage over those two methods — but pumps, seals and sensors are mechanical parts with a service life, and they are what eventually needs attention. Warranty terms and expected service intervals belong in your quote, which is why we do not publish a single generic figure here.
How much energy does the system use?
The draw is modest and continuous, because the system runs with your circulation rather than in bursts. The number that matters is kW at your flow rate: ask for it, then multiply by your own electricity tariff instead of accepting a supplier’s example calculation. In indoor facilities the larger saving often turns up somewhere else entirely — in reduced ventilation and heating load once combined chlorine falls.
Can it be combined with UV, ozone or our existing dosing system?
Yes, and combinations are common. UV is very good at destroying chloramines that already exist, while nanobubbles are aimed at preventing them from forming, so the two are complementary rather than competing. Many public facilities keep a small chlorine residual for regulatory reasons and let the nanobubble system carry the treatment load. Nanobubbles vs UV sets out where each one is genuinely stronger.
How does it compare with chlorine, salt or ozone?
We keep a separate page for each so the comparison can be detailed and fair: nanobubbles vs chlorine, nanobubbles vs a salt chlorinator and nanobubbles vs ozone. The short version: chlorine is the cheapest and best understood method there is, a salt system still makes chlorine, ozone is a powerful oxidiser limited by how much gas you can dissolve, and nanobubbles are strongest where air quality and chemical cost both carry real money.
What does a nanobubble system cost?
There is no single figure, because a municipal 25-metre pool and a hotel plunge pool are not the same purchase. Capital cost is higher than dosing pumps and drums — that is true of every alternative to chlorine. What is predictable is the shape of it: a larger up-front cost, a much smaller chemical bill, modest continuous energy use and very few consumables. Ask every supplier for total cost over five years on your actual pool volume.
Is it worth it?
It is worth it where chemical spend, air quality or bather comfort carry real financial weight: public pools, hotels, swim schools, spas and any indoor hall with a chloramine problem. It is much harder to justify on chemical savings alone for a small, lightly used private pool, and we would rather say so than sell a system that will not pay for itself. One resort pool documented 85% less chlorine against its previous dosing regime — that page shows how the figure was arrived at.
How quickly will we see a difference?
Operators usually notice water clarity first, within days of commissioning. Air quality in an indoor hall improves as combined chlorine falls, and how fast that happens depends on how much chloramine load is already in the system. Chemical consumption only becomes a meaningful number over a full season rather than a fortnight, which is also the honest horizon for judging the investment.
Is nanobubble treatment approved for public pools in Norway?
The bathing-facility regulation (forskrift om badeanlegg, bassengbad og badstu) sets requirements for water quality, monitoring and documentation rather than approving individual products, and the municipal health authority enforces it. In practice a Norwegian public pool keeps a disinfectant residual and uses nanobubbles to carry the treatment load and cut dosing substantially. What we can help with is the documentation your municipality will ask to see — that is covered on standards and compliance.
What documentation should I ask any supplier for?
Ask for kW draw at your flow rate, the service interval and what a service visit costs, what wears out and how often, the warranty terms in writing, and total cost of ownership over five years on your own pool volume. For a public facility, also ask how results are logged and how that logging satisfies the municipal health authority. A supplier who cannot produce those is quoting you a box rather than a solution. If you are specifying a municipal facility, solutions for public facilities is written for that process.
Do you supply anything outside swimming pools?
Yes. The same gas-transfer physics is used in industrial water treatment and in live fish transport, where dissolved oxygen is what keeps fish alive in wellboats and transport tanks. For wellboats, NanoSWIM supplies two systems of its own, ABAN-20 for oxygenation and ARVAND-O3 for disinfection between assignments; other industrial and aquaculture projects are handled together with our sister company NanoMAR, which specialises in that side of the work, while pools and aquatic facilities stay with NanoSWIM.
How does nanobubble oxygenation work on a wellboat?
On a wellboat, NanoSWIM's ABAN-20 module oxygenates a sidestream rather than the full well flow: seawater is taken from the vessel's recirculation loop, low-pressure oxygen from the vessel's own supply is fed in where mixing is strongest, 20 passive hydrodynamic generators turn it into nanobubbles, and the oxygen-rich water returns to the well. The design basis is 1,000 m³/h and 100 kg O₂/h per module, with one module per well recommended for distribution and redundancy. Those are design figures rather than measurements from a vessel in service, and the module is offered through a pilot programme. It adds oxygen; it does not remove ammonia. How it fits alongside disinfection is set out on wellboat oxygenation and disinfection.
Does the ABAN-20 need its own pump or a lot of power on a wellboat?
No to both. NanoSWIM's ABAN-20 wellboat oxygenation module has no pump in its scope: the sidestream is drawn by the vessel's existing seawater pump. Its 20 nanobubble generators are passive and hydrodynamic, so no electrical power is used inside the generators to make the bubbles, and the electrical load is for controls and instrumentation only — approximately 1.5–3 kW. What it does need is hydraulic capacity from that pump (the design ratio is 10 m³/h of flow per kg O₂/h), a low-pressure oxygen supply and room for a 1.5 × 0.6 × 2.0 m skid per well. The full specification is on the ABAN-20 product page.
How are wellboat wells disinfected between assignments, and how is it documented?
On a wellboat, NanoSWIM's approach is closed-loop disinfection of the empty wells, piping and associated equipment after unloading and before the next loading, with ozone delivered as nanobubbles by the ARVAND-O3 skid. The system is isolated, circulation is started, the ozone-nanobubble treatment is run, ORP and TRO (measured in seawater) are monitored against a defined contact time, and safe conditions are verified before the wells are reused. ORP and TRO are logged continuously, and that log is the basis for the documentation. Off-gas is destroyed, residual ozone is removed before discharge, and gas detection with automatic shutdown is built in because ozone is hazardous to breathe. It is not a treatment with fish on board, and it does not replace the vessel's own hygiene regime. Details are on the ARVAND-O3 product page.
What does a wellboat pilot with NanoSWIM involve?
A NanoSWIM wellboat pilot runs in five steps: a vessel assessment (tank volume, circulation loop, hygiene protocol, integration points); a concept design for the ozone, nanobubble, monitoring and off-gas configuration; disinfection trials on board between assignments in closed-loop mode; measurement of ORP / TRO, turnaround time, chemical reduction and operational savings; and only then deployment on further vessels, with service and monitoring support. The target is to cut disinfection turnaround by at least 50% while improving biosecurity control — a target the pilot exists to test, not a result already achieved. Both wellboat systems are offered through this pilot programme. The first step is to send us the vessel details.
Where to read the longer answer
Did not find your answer?
Send us the question along with your pool volume, turnover rate and current chemical spend, and you will get a straight technical answer — including when the answer is that nanobubbles are not the right fit for your facility. Ask your question and we will come back to you.