How To Know If Public Pool Water Is Clean (A step-by-step checklist)


a swimmer tests pool water using test equipment

As a regular swimmer and pool owner, I am obsessed with pool water quality. Clean pool water is essential to a healthy swim.

From public pools to private backyard pools, there is a lot involved with pool maintenance.

As a general rule, crystal clear water and a neutral smell is a good first sign of a clean pool, however other factors that affect pool water quality include the pool filtration system, regular cleaning and well-balanced pool chemistry.

In order for pool water to be deemed safe to swim in, it must look clear, smell neutral and pass chemical tests.

In this article, I will dig deeper into what you need to look out for in order to deem a public pool or your own private pool safe to swim in.

In this article I will cover:

  • Public pool water safety checklist
  • What happens if you swim in an unsanitary pool?
  • What to do if you suspect dirty public pool water

Public Pools: Pool Water Safety Checklist

Public pools are often the only option for swimmers who want to swim for fitness, but how do you know if your public pool water is safe, and healthy to swim in?

I have swum in many public pools and seen a range of pool water quality. Although I have never had a sick stomach, I have picked up ear infections at pools that I should have known would cause me problems.

Unless you are the type of person who carries a water test kit in your swim bag, it is unlikely that you will really know what the quality of a public pool is. However, there are things you can check to ensure that the body of water you are using regularly is safe to swim in.

Here is a step-by-step guide to deciding if your public pool is healthy to swim in every day.

1. Is The Water Crystal Clear?

Good quality pool water should be crystal clear.

Not only should it be free from surface floating debris, but you should also be able to see clearly underwater with goggles on. This includes being able to see right to the bottom of the deepest diving pools.

You may come across a pool that is cloudy. In this case, either one of two things has failed:

  1. The pool filtration system is not working well.
  2. The pool chemicals are not correctly balanced.

I recall swimming at a pool where the water turned a milky, cloudy colour. I was a member of a very popular swim and spa franchise in the UK at the time and swum every day.

Every morning at 7am, the pool staff would take a chemical reading and after some questioning, they told me that the cloudy water resulted from the pool filtration system, which was not working well.

In addition, some white round stones had appeared on the floor of the pool.

I was assured that it was just a temporary glitch, and the water was safe to swim in.

However, after a few days of cloudy water, the water became so cloudy you could hardly see your hand in front of your face.

For me, I had enough and given the high cost of this pool membership, I quickly cancelled and found a new pool.

Although the staff reassured me that the water quality was fine, the fact that it was cloudy, and had what appeared to be some sort of chemical stones accumulating on the pool floor, made me uncomfortable and not satisfied.

So in a nutshell, if you are going to be swimming every day or trying out a new pool, ensure your pool water is crystal clear.

2. Does It Smell Of Chlorine? (Or anything else)

After a visual test to ensure the water is crystal clear, the next thing you can inspect is the smell.

In a perfect world, your public pool will have a neutral smell.

Chlorine is often used to disinfect public pools, and it has a strong smell that can be recognised easily.

Many swimmers think that a chlorine smell is a good thing, but this is not the case.

As a general rule, a strong chlorine smell tells you that the pool does not have enough chlorine. A chlorine smell comes from chemical compounds called chloramines, which form when chlorine and substances such as urine, sweat, and cosmetics combine with the chlorine.

It is not the chlorine itself that you are smelling, but these chemical chloramine compounds.

The solution to a pool that smells too strongly of chlorine is to add more chlorine. [source]

In summary, if your public pool has a really strong chlorine smell, this tells you that the pool operators are not adding enough chlorine. More chlorine results in a cleaner and better disinfected pool as long as the chlorine levels are kept within a healthy range.

3. What Does The Water Feel Like?

This might sound like a strange one, but if you have ever swum in a fresh pool where the water has just been changed, you will know exactly what I am talking about.

If you touch the pool water and try to rub it between your fingers, it should feel soft and clean with no oily residue.

I had the privilege once of being the first person to swim in a public pool where the entire body of water had been changed.

The pool was closed for cleaning, so when I was the first in, I got to experience what a truly spotless pool feels like.

I will never forget it. The water felt soft, fresh and almost drinkable! It felt like the water was giving me one great big hug.

It made me question the state of all public pools once I had a pristine pool to compare to, but I learned a valuable lesson and that is to pay attention to the feel of the water.

If the water feels oily or grainy, then it is far from perfect. It will most likely still be safe, but if the water does not look, smell, or feel right, then it is not a great place to be.

4. Is The Pool Water Regularly Tested?

Here in the UK, pool operators are legally required to protect the health and safety of pool users.

The UK HSE (Health & Safety Executive) provides full advice on what the person in charge of a swimming pool needs to do to comply with health and safety laws. You can read the full document on this website. [source]

Part of maintaining a pool and keeping it safe for swimmers is to complete regular testing.

Such tests involve looking at the PH level, the chlorine and pool chemical levels, the alkalinity and more.

If you are in doubt (or just curious like me!) you can ask the duty manager in charge of the pool about how the water is, or how regularly it is tested or if they have a pool inspection sheet they can share.

Any good pool will happily tell you about all the testing and checks they do on the water to maintain a good water quality level.

You may even see someone completing these tests. Generally, a pool worker will take a sample of water from the pool. It is as simple as someone walking to the water’s edge and taking a sample for testing. This is typically part of the process for testing the pool chemistry.

Depending on the chemical system in the pool, most public pools will test every 2-4 hours.

5. Are There “Shower Before You Swim” Signs?

As mentioned previously, a strong chlorine smell happens because of too little chlorine in the pool, and chemical compounds called chloramines react with ammonia in substances such as urine, sweat, and cosmetics.

In order to keep the pool clean and reduce the about of bad substances in the pool, it is essential that everyone showers before getting into the pool.

This will reduce the amount of sweat or cosmetics a swimmer is taking into the pool with them.

Water Filters That Remove Microplas...
Water Filters That Remove Microplastics

All good pools will have clear signage indicating that is essential to shower before using the pool. This will tell you that the pool cares about good hygiene.

6. Are Swimming Caps Compulsory?

In the UK, it is not compulsory to wear a swimming cap at public pools. I have yet to find a pool that requires every swimmer to wear a swim cap.

In countries such as Ireland, swimming caps are typically mandatory in all public pools. Every swimming pool I have visited in Ireland required a swimming cap.

Swimming pools that require swim caps to be worn are noticeably cleaner.

As well as helping you swim faster and keeping hair out of your eyes, swim caps also prevent hair and chemicals on the hair from mixing with the pool water.

Swimming pools that require swim caps as mandatory will find that their filtration system will be under less stress as it will not be as blocked with hair.

In addition, swim caps can keep a lot of hair product chemicals out of the water, which will keep it cleaner. [source]

7. Are The Changing Rooms Clean?

When I assess the quality of a public pool, I also consider the changing rooms.

Although changing rooms do not affect the quality of the pool water, the standard of cleanliness in the changing rooms will tell you how much attention to detail the pool owners pay to hygiene.

I have direct experience of this from a pool I swam in many years ago.

The pool was based in North London, and although the quality of the water seemed good, the changing rooms were terrible.

I don’t want to gross you out, but the walls were visibly dirty.

After my one swim in this pool, I developed a terrible ear infection.

Typically, I dry my ears thoroughly after my swim to reduce the risk of ear infection, but I still got one from this pool and it was bad.

From this experience, I learned to judge the cleanliness of the entire swimming complex and not just the quality of the pool water.

Pool water may look and smell clean, but it may have bacteria you cannot see.

What Happens If You Swim In An Unsanitary Pool?

The water quality of public pools is generally out of our control as recreational swimmers.

Although a pool might look clean, it may contain bacteria and germs that you cannot see which can make you ill.

As a general rule, recreational water illnesses (RWIs) such as diarrhoea, ear infections, coughs, eye pain and skin rashes are common symptoms of swimming in an unclean pool. Just a mouthful of unsanitary water can make you ill.

The symptoms of recreational water illness can range from mild to severe, with diarrhoea being one of the most common symptoms. [source]

What To Do If You Suspect Dirty Public Pool Water

As public users of public swimming pools, we do not really know how safe the water is as we cannot see the bacteria that cause upset stomachs and other ill effects.

Although we can take practical steps such as ensuring the pool water is clear, ensuring there is no floating debris, ensuring there is not a strong chlorine smell, checking the pool completes regular testing etc, what should you do if you are not happy or suspicious of the water?

1. Talk To The Duty Manager

Most pools will have a notice on the wall about who you should talk to if you have concerns about the quality of the pool.

Our first instinct is to speak to the lifeguard, but it is not a good idea to distract a lifeguard with a lengthy conversation, especially if they are the only lifeguard on duty!

All good pools will have notices up about who to talk to. If in doubt, just go to the pool reception and raise your concerns.

2. Shower Thoroughly

Ensure you shower thoroughly to remove any contaminated water from your body after your swim.

3. Dry Your Ears

Ensure you dry your ears thoroughly. If you allow unhygienic water to remain in your ears after your swim, this could cause a nasty ear infection.

Some swimmers choose to wear swim ear plugs to prevent water from getting into the ears. I have covered this topic in much greater detail in this article, “Do Swimming Ear Plugs Stop Water Getting In Ears?”

4. Don’t Swim

Prevention is better than cure and if you are not satisfied with the cleanliness of your public pool, don’t swim.

Try to find an alternative pool or report the water quality to the pool manager.

Final Thoughts

Public pools are a wonderful service, but it is important to be aware of the risks associated with swimming in unclean water.

Although pool owners take many steps to ensure the quality of their pool water, it helps if swimmers are vigilant and can spot the signs of dirty pool water, particularly if visiting a new pool or going on holiday.

If you have any concerns about the quality of your pool water, talk to the duty manager first or find an alternative pool.

Recreational water illness is common amongst those who swim in contaminated or unhygienic pool water and symptoms typically include diarrhoea, skin rashes or ear infections.

At the end of the day, it helps to understand what clean pool water looks like so you can protect your health and continue to swim regularly.

Happy swimming!

Louise Byrne

Hi, I am Louise and I am obsessed with swimming. I spend my free time in the water or getting ready for my next water adventure.

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