14 August 2014
How your swimming pool works
Swimming pools come in many shapes and sizes and, on the face of it, appear to be fairly simple – just big tanks of water. However, there is a lot of unseen smart technology working away in and around your pool which helps to keep your water clean, safe and chemically balanced.
All pools work in much the same way by using a combination of filtration and chemical treatment to constantly clean a large volume of water. Your swimming pool will have a motorised pump, a water filter, drains and a plumbing system to connect everything together. All of the items of equipment interact to ensure that your pool runs efficiently.
The pump is at the heart of your pool, in fact, if you compare it to the human heart it does a similar job by maintaining and delivering a flow of liquid around your pool system. It’s recommended that your pump is programmed to come on for a minimum of 12 hours per day; but bear in mind that the more the pump runs the better your pool will perform.
Once the pump is activated it pushes the pool water towards the skimmers, catching the largest debris (leaves, insects etc) in the strainer basket. At the same time, the main drain at the bottom of the pool collects the colder water for better mixing. This is important to ensure that the pool chemicals are distributed evenly throughout and to ensure the water is evenly heated.
The pump collects and sucks up all the available water and sends it directly to the filter. If your pool is deck level, the overflow grate will catch the water.
The filter’s main function is to screen out any impurities to make sure that your pool is full of clean water only. There are different types of filters (eg sand, glass, cartridge etc). If you have a sand filter, for example, any dirt and foreign bodies in the water are trapped between the grains of sand. It’s important that your pool maintenance company backwashes your filter to clear out the dirt from between the sand grains or glass particles every week. This will keep your pool safe for bathing and ensure it lasts longer. If you have a cartridge type filter, it is important that the cartridge element (which does the filtering) is removed and cleaned on a regular basis, which you or your service engineer can do. All types of filters require regular maintenance to ensure peak performance and longevity.
After the clean water has been through the filter it is at this stage that it will be heated. There are many types of heater. Gas and oil swimming pool heaters work by burning the fuel to heat the water as it passes through special pipes in the unit. Electric heaters work by passing the water over a heating element not unlike a kettle. Heat pumps are refrigerators in reverse they use a relatively small amount of electricity to compress a gas which then expands and draws heat from the air to heat the water. Solar heaters or ground source heat pumps take their heat from beneath the ground.
Pool water needs to be sanitised to ensure that it is safe for swimming. Just because the water looks crystal clear it doesn’t mean that it is safe. Bacteria will rapidly multiply in pool water that remains untreated. In the UK, the most widely used water treatment for domestic pools is chlorine, although there are other alternatives such as bromine. In addition to chlorine or bromine, ultra violet (UV) and ozone is widely used, this allows you to run your chlorine or bromine level at a much lower level than you would without UV or ozone. Your service engineer will advise on what is best to use in your pool.
pH is the most important element in swimming pool water chemistry – it affects every other chemical balance in the pool water. pH is a scale for measuring the pool's acidity or alkalinity level. In pools, a slightly alkaline level between 7.2 and 7.6 is ideal because this range is the most comfortable to the human eye, provides optimum use of free chlorine and provides water that is non-corrosive or scale forming.
As well as measuring the pH level, your service engineer will also test for total alkalinity, water hardness, totally dissolved solids, cyanuric acid and other factors and choose the right treatment for the pool water. Correct water treatment will ensure your pool is safe for swimming and keep it in great condition.
Your pool and equipment will need regular and professional maintenance to keep everything in tip-top condition. It’s crucial to check how long your maintenance company has been in business and what qualifications the members of the team have. A company with a long record and skilled engineers will be able to use its experience to ensure your pool performs well and cost-efficiently. The company will also be able to spot any possible problems immediately and save unnecessary problems and repair bills.
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.