swimming pool construction London


02 November 2015
What do the chemicals in your pool actually do?

Whether you’re looking at buying a pool for the first time or a long-term pool owner, you’ll no doubt be aware that a number of steps are taken to ensure that a pool – be it indoor or outdoor – is clean and safe for human use.

Not only do pools feature complex filtration systems, as well as air and water temperature controls, in order to combat germs and other contaminants, they also feature a number of different types of chemicals, including various disinfectants and sanitisers.  But do we really understand what they do and does it matter?  We think so – that extra bit of knowledge will ensure that you make pool care a priority and avoid mishaps. The trick to good pool care is ‘little and often!’

Generally speaking, pool chemicals are there to regulate the levels of contaminates in the water and for bather comfort. You might already be aware that chlorine is one of the most common, but what about the others – and just how important are they to the proper functioning of your pool? Let’s look at some of the key types of pool chemicals and why they are necessary.

Each swimmer in a pool is said to add one thousand to one million microbes to the water - which itself is full of micro-organisms. The point of pool disinfectants is to destroy these and ensure the pool is safe to swim in.

The most common disinfectant is chlorine, usually in the form of hypochlorite or hypochlorous acid. The main difference between them, apart from price, is concentrations. While its intended purpose is to kill the aforementioned pathogens and microbes, too much chlorine can irritate the skin, eyes and sinuses. If the chlorine concentration is too low, the risk of problems is, of course, higher.

As well as this, the efficacy of your disinfectant is affected by variables such as bather load, pH levels and temperature. For all these reasons, it’s important to strike the right balance when it comes to the levels of pool disinfectant used. Your pool technician will be fully aware of the thresholds and maximum levels of disinfectant for your specific pool.

pH Correctors
One of the most important aspects of pool chemistry is the pH levels of the water:  In simple terms, pH is an indication of whether the water has acid or alkaline properties and total alkalinity is a measure of how much alkaline substances are in the water.

As our previous blog post states, a number of problems can occur if pH levels are not kept in equilibrium. Highly acidic water (low pH) can cause structural damage to the pool and equipment, as well as irritate the eyes, skin, and hair of swimmers. Meanwhile, high pH levels can cause scale and calcium deposits to form which damage filtration equipment, and can also render chlorine and disinfectant useless.

It’s obvious, then, that pH levels of pool water need to be closely regulated and controlled (at about a pH of 7.2-7.6) to ensure the structural integrity of the pool as well as the health of bathers. This can be achieved with the help of pH correctors.  If there is low pH in your pool, sodium carbonate (or soda ash), for example, can correct this. If the total alkalinity is low, bicarbonate of soda may be used to equalise this and ensure pH does not fluctuate sporadically. You can read more here.

Perfect Water Balance
As well as ensuring the regular chemical balance of the pool is correct, it’s also important to ensure your pool is cleaned regularly. Your pool servicing engineer will provide the cleaning supplies which should be used on a regular basis in order to maintain the pool’s chemistry. These include:

  • Chlorines – to sterilise the water.
  • Algaecides – like the name suggests algaecides deal with algae growth in the pool. These are either Poly Quarternary ammonium compounds or copper-based, and affect different types of algae differently.
  • Clarifiers and flocculants – if water is cloudy due to the use of pool chemicals or very fine debris, clarifiers and flocculants clump together these small particles into bigger masses which the pool filter can collect more easily.
  • Stain removers – while there are many types of stain remover, their primary general purpose is to remove so-called ‘scum lines’ from the side of pools or general stains on equipment such as ladders and handrails.

While filtration systems do a lot of the ‘legwork’ in terms of keeping your pool clean, you can view pool chemicals as a way of ‘fine-tuning’ that process. Chemicals make maintenance a lot easier, and along with regular cleaning and servicing by your pool engineer, you’ll be well on your way to keeping a healthy, clean, beautiful pool.

At London Swimming Pool Company we specialise in swimming pool maintenance, servicing and refurbishment, so if you have a pool that’s in need of regular maintenance or a facelift, contact us for an initial discussion – there’s no substitute for expert advice. If you have an older swimming pool that needs upgrading, we suggest planning your refurbishment for the autumn, so all the work is done and dusted before the next swimming season.

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