If your swimming pool is not properly maintained then the water in your swimming pool may contain a range of germs, including bacteria and viruses. Some germs can cause health problems, such as ear, nose and throat infections.

You should check your swimming pool regularly to ensure that the water quality is safe for you to swim in. A simple way to do this is to look into the pool each day and check: 

  • Is the water clear? 
  • Can you see to the bottom of the pool? 
  • Does the water look any different to how it looked the day before? 

Any changes, such as cloudiness and/or a change of water colour are a clear indicator that you should test the water and take steps to improve water quality before anyone goes swimming in the pool. 

Sources of contamination in swimming pools

Doctors calculate that there can be any one or more of up to thirty different types of bugs/diseases in a swimming pool. Cryptosporidium and E.coli, both of which cause vomiting and diarrhoea, are caused by faecal material. Giardia is a parasite that causes chronic diarrhoea, whilst bacterium called Pseudomonas aeruginosa is responsible for skin and ear infections. Another harmful bug is Acanthamoeba which attacks the surface of the eye causing painful inflammation. 


Potential sources of microbes in your pool may include: 

  • People swimming in the pool – this is the main source of microbes (especially if the person did not shower prior to entering the pool). 
  • Animals, such as dogs – some pets like to paddle in the pool on hot days. 
  • Dead wildlife – for example, mice, frogs, lizards or insects may occasionally drown in your pool. 
  • Debris from around the property, such as leaves, grass and dust.

Swimming pool maintenance

The five keys to maintaining water quality in your swimming pool include: 

  • filtration 
  • chlorination 
  • pH level 
  • total alkalinity (TA) 
  • calcium hardness.



Swimming pool filtration

The water in your pool is pumped through a filter to remove debris and particles. The period of time required for you to run your pump/filter depends on the size of your swimming pool and the horsepower of your pool pump. If you are unsure then Bespoke Property Management Ltd will check that your swimming pool equipment is adequate versus the pool water volume/mass in your swimming pool. The general rule is that the contents of your swimming pool should be able to pass through the filtration system within 8 hours of the pump being switched on in any given 24 hour period.

Most pool filtration systems are not able to filter all the water in the pool as most pools will have a dead point within the pool (a point/area where the water barely moves unless in use). Chlorination is a common and effective treatment often used alongside filtration to inactivate microbes that may be present in the pool water. The best maintained pools rely on multiple treatment barriers. 

Chlorination for swimming pools

Chlorine is a chemical that disinfects the water and helps to remove/kill bacteria. You should use a chlorine stabiliser to extend the chlorine's half-life. Generally, the longer your filtration cycle, the less chlorine you will need. Similarly, the more chlorine you use, the shorter your required filtration cycle.

Remember that your chlorine requirements will be affected by a range of factors, including your pump and filter system, water temperature, water level, amount of debris and the number of swimmers/bathers in your pool.

pH level in swimming pool water

The pH level indicates how acidic or alkaline the water is at any given time. A pH level of 7 means that water is neutral; above 7 means the water is alkaline, while below 7 indicates acidity. Aim for a pH level of between 7 and 7.6. If the water pH is higher than 8, anyone who swims in the pool is at risk of skin rashes, while a pH of lower than 7 can sting swimmers' eyes.

Some of the many factors that can affect your pool's pH level include heavy rain, the number of swimmers in the pool and chemicals. Remember to regularly check the pH level. 

Total alkalinity and swimming pools

Total alkalinity means the sum of all alkaline chemicals in your water. If the total alkalinity is too low, the pH balance can become unstable. Concrete and painted pool surfaces will also deteriorate over time. The total alkalinity and pH are interconnected. For example, raising the total alkalinity could also raise the pH. Make sure you don't disrupt your pool's pH when adjusting the total alkalinity and vice versa.


Calcium hardness in swimming pool water

Calcium hardness refers to the amount of the mineral calcium dissolved in your water. Low calcium levels will deteriorate pool surfaces, while high calcium levels will leave a 'scum' or scale on surfaces and equipment.

Call Bespoke Property Management Ltd for information on how to maintain good water quality in your swimming pool. Ways to maintain pool water quality may include: 

  • Checking pH and chlorine levels daily. Preferably before the first swim of the day to make sure the water quality hasn't altered overnight. 
  • Checking the pH and chlorine daily in very hot weather. 
  • Monitoring chlorine levels in heated pools which need more chlorine than non-heated pools. 
  • Brushing and vacuuming your pool on a regular basis. 
  • Regularly checking the pump, skimmer boxes and other pool equipment, and repair or replace parts as necessary.
  • The age of the water and filter media.

Solving common swimming pool problems

Bespoke Property Management Ltd can provide advice about other common water issues/problems, which may include algae, faeces or a chlorine smell in your pool. We also construct and repair pools. Your pool equipment should be regularly checked for leaks, effectiveness and efficiency. Servicing your pump, changing your filter media and/or water will also have a very positive outcome in terms of water clarity and comfort for the person using the pool. Testing with the latest equipment and acting upon the results of such tests is also the key to a perfect bathing experience.

Algae in swimming pools


Algae are single-celled organisms that grow quickly in the right conditions and can turn the water in your swimming pool green within a few hours. Chlorine will help prevent growth of algae. Treatment to remove algae includes lowering the pH level of pool water by adding pool acid and, later, adding a copper treatment to the water to kill the spores.

You can use a brush and garden hose to remove algae from pool surfaces. The next day, vacuum the settled algae from the floor of your pool - don't try to remove it by running the filter. Make sure you check the TA, pH and calcium hardness before you allow anyone to swim.

Faeces in swimming pools

Young children can occasionally have a faecal accident while swimming. Get everyone to vacate the pool and remove as much of the faeces as possible using a fine mesh scoop. If your pool is small, you might consider draining and cleaning it. Otherwise, add a concentrated (10 mg/L) dose of chlorine to the pool, filter continuously and don’t allow anyone to re-enter the pool for at least four hours.
Make sure you check the chlorine levels have dropped back to regular levels before anyone re-enters the swimming pool.

Strong chlorine smell in swimming pools

A strong chlorine smell can affect the eyes, nose and skin. Contrary to popular belief, it's too little chlorine that causes the smell, not too much. Too little chlorine permits chloramine compounds to form. It is these compounds that have the strong smell and that cause the irritation. If your pool smells strongly, check the chlorine level as you may need to add more chlorine.

Safety suggestions for pool chemicals

Pool chemicals can be dangerous if not handled properly. Suggestions include: 

  • Keep pool chemicals away from other chemicals and locked up in a cool, dry place. 
  • Do not store pool chemicals near other chemicals or flammables, including petrol, detergents or alcohol. 
  • Always use chemicals strictly as instructed. 
  • Never combine chemicals together – for example, mixing different types of chlorine together (such as granular and liquid) can cause an explosion. 
  • To avoid splashing the chemicals, always add the chemicals to water and not the other way around. 
  • Don't add the water to the chemicals. 
  • If you are splashed, rinse contaminated clothing straight away and wash your skin thoroughly in plenty of water.

Things to remember

  • People swimming in the pool are the main source of contamination. 
  • The keys to maintaining water quality in your swimming pool include filtration, chlorination, pH level, total alkalinity (TA) and calcium hardness. 
  • Check your pH and chlorine levels daily – preferably, these tests should be done before the first swim of the day to make sure the water quality hasn't altered overnight. 

What is a CPO and who are the NSPF?

A CPO a certified pool and spa operator. The CPO is accredited with this qualification by the National Swimming Pool Foundation upon completion of the compulsory training plus gaining the necessary pass mark during a thorough examination/test. 

Here at Bespoke Property Management Ltd we do not gamble or take risks with you or your family’s health. All of our pool technicians are CPO trained including the management/directors of BPM.