# Swimming SPF

> A UK reference on swimming as a water chemistry and duty of care problem. Treated pool
> water, indoor and outdoor pools, lidos, open water, organised sessions, schools, clubs
> and children. Written for the individual swimmer and for the person running the session.

Published by Northbank Media. Last reviewed 7 August 2026.

## What this site does not contain

- No product recommendations of any kind, including sunscreen. No affiliate links.
- No named pool, club, swim school, facility, training provider or company in the editorial.
- No chemical concentrations, dosing values, water parameter targets or water quality figures.
- No prices, no invented studies, no invented statistics, no case studies.
- No clinical advice. Clinical questions are referred to a pharmacist, a GP or NHS 111.

## Structural devices

- Who owns this: one decision split between the swimmer, the session leader and the facility
  operator, with the guidance or instrument named where a duty attaches.
- Indoors or outdoors: the same question answered separately for an indoor hall and an
  outdoor pool or open water, because the answers differ.

## Sections

### Pool water (https://www.swimmingspf.com/water)

Treated pool water is a managed chemical system, not a tank of chlorine. This section covers what is in it, what swimmers add to it, why the smell of a badly run hall means the opposite of what most people assume, and who is qualified to hold the decisions.

- [What pool water actually is, and why calling it chlorine explains nothing](https://www.swimmingspf.com/water/what-is-in-pool-water): Treated pool water is a managed system of circulation, filtration, disinfection and pH control, not a tank of chlorine. What each part does and who holds it.
- [Combined chlorine and chloramines: why the smell means the opposite of what people assume](https://www.swimmingspf.com/water/combined-chlorine-and-chloramines): The swimming pool smell is not chlorine doing its job. It is chloramines, formed when disinfectant reacts with what swimmers bring in. What that tells you and who can fix it.
- [What swimmers add to the water: sunscreen, cosmetics and the chemical load](https://www.swimmingspf.com/water/what-swimmers-add-to-the-water): Sunscreen, moisturiser, hair product, deodorant and make up all enter the water with the swimmer. What that does to a treatment system, and how to handle it without giving up sun protection.
- [Why pools ask you to shower first: hygiene, chemistry, or both](https://www.swimmingspf.com/water/shower-before-swimming): The pre swim shower is a chemical intervention as much as a courtesy. What it actually removes, why it changes the water, and why so few swimmers do it properly.
- [Who actually treats the water, and what qualification sits behind it](https://www.swimmingspf.com/water/who-treats-the-water): Pool water is dosed, tested and adjusted by named people with specific training. Who they are, what a pool plant operator qualification is, and where the legal duty sits.
- [What gets tested, how often, and what a swimmer can reasonably ask to see](https://www.swimmingspf.com/water/water-testing-and-records): Pool water is tested repeatedly through the day and recorded. What the tests are for in structural terms, what the records exist to prove, and what a swimmer can ask.

### Indoors (https://www.swimmingspf.com/indoors)

An indoor pool hall removes the sun problem and replaces it with an air and water problem. This section separates the two so that outdoor habits are not carried indoors, and indoor complacency is not carried outdoors.

- [Indoor pools and ultraviolet: why the sun question mostly disappears](https://www.swimmingspf.com/indoors/indoor-pools-and-uv): Ordinary building materials stop the ultraviolet that matters, so an indoor pool is not a sun exposure environment. What that does to the whole product question indoors.
- [Should you wear sunscreen at an indoor pool](https://www.swimmingspf.com/indoors/sunscreen-at-an-indoor-pool): There is no ultraviolet exposure to protect against indoors, and the product adds load to the water. The straightforward answer, and the edge cases where it changes.
- [Indoor pool air, ventilation and why the hall smells](https://www.swimmingspf.com/indoors/indoor-pool-air-and-ventilation): The indoor environmental problem is air, not sun. What accumulates above the water, why ventilation is the control, and who owns it.
- [Glazed roofs, rooflights and the one indoor case worth checking](https://www.swimmingspf.com/indoors/glazed-roofs-and-rooflights): Ordinary glass blocks the ultraviolet that causes sunburn. What that means for heavily glazed pool halls, retractable roofs and the questions worth asking an operator.
- [Planning an indoor session: what the leader actually needs to think about](https://www.swimmingspf.com/indoors/planning-an-indoor-session): With ultraviolet off the list, an indoor session plan is about air, water, temperature, supervision and the parts of the day that are not in the pool.

### Outdoors and lidos (https://www.swimmingspf.com/outdoors)

An outdoor pool is a reflective surface, a long dwell time, very little clothing and repeated immersion. This section covers what that does to exposure, what an operator can actually change, and how a session gets timed.

- [Outdoor pools and lidos: the exposure environment nobody plans for](https://www.swimmingspf.com/outdoors/lidos-and-outdoor-pools): An outdoor pool combines long dwell time, minimal clothing, a reflective surface and the middle of the day. Why that compounds, and what changes about the water too.
- [Reflection, scatter and why water changes the exposure picture](https://www.swimmingspf.com/outdoors/reflection-and-the-water-surface): A water surface reflects and scatters light, adding exposure from angles that shade and hats do not cover. What that means for the face, the eyes and where sunburn actually appears.
- [What an outdoor pool operator can actually do about shade](https://www.swimmingspf.com/outdoors/shade-at-an-outdoor-pool): Shade is the most effective intervention at an outdoor pool and it is entirely an operator decision. What good shade looks like, what gets in the way, and what to ask for.
- [Timing an outdoor session around the ultraviolet index](https://www.swimmingspf.com/outdoors/timing-an-outdoor-session): Timing is the most effective and cheapest sun protection available, and for organised sessions it is a decision somebody makes on a timetable. How to use it.
- [Reapplying around swimming: the practical sequence](https://www.swimmingspf.com/outdoors/reapplying-around-swimming): Getting in, getting out and towelling all interrupt protection. How to sequence application around a swim, and why the group version is different from the individual one.

### Open water (https://www.swimmingspf.com/open-water)

Open water is a different environment from a pool in every respect that matters: temperature, visibility, glare, water quality classification, and the fact that nobody dosed it. This section covers the checks, the classification system and the group question.

- [Open water as an environment: cold, wind, glare and nobody dosed it](https://www.swimmingspf.com/open-water/open-water-as-an-environment): Open water differs from a pool in every respect that matters: temperature, visibility, glare, water quality and the absence of any treatment system at all.
- [Bathing water classification and where to check it](https://www.swimmingspf.com/open-water/bathing-water-classification): Designated bathing waters in the UK are sampled and classified each season. What the classification describes, what it does not, and where to look it up.
- [Sea, estuaries and inland water: how the environments differ](https://www.swimmingspf.com/open-water/sea-estuaries-and-inland-water): Salt water, brackish estuaries, lakes and rivers behave differently for visibility, temperature, water quality and glare. What changes between them.
- [Planning a wild swim: the checks before you get in](https://www.swimmingspf.com/open-water/planning-a-wild-swim): An unsupervised open water swim moves every check onto the swimmer. What to look up in advance, what to look at on arrival, and what to plan for the whole session.
- [Cold water, wind and everyday skin care afterwards](https://www.swimmingspf.com/open-water/cold-water-wind-and-skin): Cold and wind change what skin feels and hides the signals people rely on. Ordinary everyday care afterwards, and the point at which this becomes a question for a pharmacist.
- [Open water groups and who is looking after whom](https://www.swimmingspf.com/open-water/open-water-groups-and-supervision): An organised open water session moves the checks from the individual to the leader. What that means, where the line between a group of friends and an organised session sits, and what changes at it.

### Duty of care (https://www.swimmingspf.com/duty-of-care)

Schools, clubs, swim schools, lessons and organised open water sessions all move decisions away from the individual swimmer. This section works out who holds what, what a session risk assessment should reach, and where the instruments sit.

- [Who holds the duty of care at a swimming session](https://www.swimmingspf.com/duty-of-care/who-holds-duty-of-care): Swimming happens under supervision more than almost any other activity. Who holds what between the swimmer, the session leader and the facility operator, and where the instruments sit.
- [What a swimming session risk assessment should cover](https://www.swimmingspf.com/duty-of-care/session-risk-assessment): A useful assessment is short, specific to this venue and this group, and covers the parts of the session that are not the swim. What belongs in it and what does not.
- [Schools, swimming lessons and the sun question](https://www.swimmingspf.com/duty-of-care/schools-swimming-and-the-sun-question): Curriculum swimming is usually indoors, on a tight timetable, with a coach journey attached. Where the sun question actually appears, and who holds each part.
- [Clubs and squads: outdoor training and the responsible person](https://www.swimmingspf.com/duty-of-care/clubs-squads-and-outdoor-training): Clubs are run by volunteers with real duties. Where responsibility sits for training timetables, outdoor sessions and the exposure of athletes and coaches alike.
- [Children in water: how supervision and sun cover interact](https://www.swimmingspf.com/duty-of-care/children-in-water): Every task that pulls an adult's eyes away from the water is a supervision cost. Why sun protection for children has to be scheduled rather than improvised.
- [Lifeguards and poolside staff: an occupational exposure question](https://www.swimmingspf.com/duty-of-care/lifeguards-and-poolside-staff): Outdoor poolside staff work full shifts in the sun, in fixed positions, with a required view of the water. That is a workplace exposure with an employer duty attached.
- [Competitive swimmers: goggles, caps, repeated immersion and what is practical](https://www.swimmingspf.com/duty-of-care/competitive-swimmers): High volume swimmers spend more hours in treated water and pool hall air than anybody. What is practical for them, and what changes on outdoor gala days.
- [What a good outdoor session plan looks like for a group](https://www.swimmingspf.com/duty-of-care/an-outdoor-group-session-plan): The individual advice does not scale. A group plan needs scheduled stops, named responsibilities, a stated cancellation rule and coverage of the whole session rather than the swim.

### Afterwards (https://www.swimmingspf.com/afterwards)

What chlorinated water and salt water do in ordinary terms, what a swim cap is and is not for, why goggles matter beyond comfort, and how shared changing facilities work. Where a problem starts, this section stops and points at a pharmacist or a GP.

- [Skin after chlorine: everyday care, and where this stops being our subject](https://www.swimmingspf.com/afterwards/skin-after-chlorine): What treated water does to skin in ordinary terms, the everyday routine that follows a swim, and the clear point at which this becomes a question for a pharmacist or a GP.
- [Skin after sea water: everyday care and nothing more](https://www.swimmingspf.com/afterwards/skin-after-salt-water): Salt, sun and wind together are drying, and the routine after a sea swim is short. What is ordinary, and the clear point at which it becomes a clinical question.
- [Eyes, goggles and glare on water](https://www.swimmingspf.com/afterwards/eyes-goggles-and-glare): Goggles are the most underrated piece of swimming equipment. What they do in water, what they cannot do about glare, and where eyes become a clinical question.
- [Hair and swim caps: what a cap is and is not for](https://www.swimmingspf.com/afterwards/hair-and-swim-caps): A swim cap is not waterproof and was never meant to be. What it actually does for the swimmer, for the pool and for supervision, and the ordinary routine afterwards.
- [Hygiene in shared changing facilities](https://www.swimmingspf.com/afterwards/changing-room-hygiene): Changing rooms are warm, wet, shared and hard surfaced. What that means in ordinary terms, what the operator owns, and where a problem becomes a clinical question.

## Publication pages

- [About and funding](https://www.swimmingspf.com/about)
- [Editorial standards](https://www.swimmingspf.com/editorial-standards)
- [The paid register](https://www.swimmingspf.com/register)
- [Register criteria, rates and refusals](https://www.swimmingspf.com/register/criteria)
- [Newsletter and sponsorship](https://www.swimmingspf.com/newsletter)
- [Contact](https://www.swimmingspf.com/contact)
- [Privacy](https://www.swimmingspf.com/privacy)

## How this site is funded

Two declared lines. A paid register of pools, swim schools, clubs, lifeguard training
providers and pool plant operators: alphabetical, marked paid, never a ranking, never a
safety endorsement, with published criteria, rates and refusals. And a newsletter with one
labelled sponsor line at a published flat rate. No advertising, no affiliate income, no
paid links, no sponsored articles. Every outbound link on the site is nofollow.