swimming pool construction London


13 March 2015
Which filter for your pool?

Even the most illustriously designed swimming pool, complete with cascading waterfalls and picturesque rock formations, will not be inviting if the water isn’t crystal clear. If the water looks dull and unappealing, this is probably due to a buildup of impurities caused by inadequate pool filtration equipment. There are two main types of pool filter - sand and cartridge. There is also the option of swapping sand media for glass media filtration. Each option has its own unique attributes, which we cover in this blog.

Sand filters
Due to their ease of installation and low maintenance, sand filters are the most popular types of filter. Sand filters are usually made from fibreglass, thermoplastic or metal and contain silica sand to filter out impurities in the water. As dirt accumulates in this bed of sand, it is recommended that a backwash is performed about once a week to flush all debris away via a waste outlet.  Sand filters are fitted with a pressure gauge to give you a clear indicator of the right time to backwash. Over time, the quality of the sand will degrade, so it is recommended that a professional pool company changes the sand every three to five years.  It is important to purchase the sand media from a specialist pool company to ensure that you are getting quality sand.

Cartridge filters
This type of filter works by forcing the pool water through a very fine cartridge. During this process, the cartridge material filters out any impurities. While cartridges should be replaced every few years, cleaning the cartridge on a weekly basis is recommended for peak water performance. Cleaning the cartridge is an easy procedure; it simply requires removing the cartridge and giving it a thorough hose down (or soaking it in degreasing agents if you want to be extremely thorough), drying it and reinstalling it - all of which should take a few minutes.  Regular cleaning will extend the life of the filter.

As with sand filters, cartridge filters are generally considered to be low maintenance. Because cartridge filters cover a higher surface area, they are more effective at catching dirt particles and are not as energy intensive as sand filters which help with running costs (though the upfront cost of a cartridge filter is higher than a sand filter). Cartridge filters do not require backwashing, so there is less water consumption which is good for the environment.

Glass media
The latest trend in swimming pool filtration is to use conventional sand filters but replace the bed of sand with recycled glass media.  Because glass particles are imbued with a slightly negative charge, this helps to attract dirt during the filtration process and release the dirt during backwashing.  Many pool-owners who have moved to glass filtration have reported that their water is cleaner than ever! Because of the strong structure of glass particles, they are far more resistant than sand to degradation which tends to occur after numerous backwashing cycles.  Because of this, glass media can still provide effective filtration for as long as 15 years before being replaced - significantly longer than sand media. While glass offers unrivalled filtration, it is the most expensive option in the short-term. However, because it doesn’t need to be replaced as frequently, this will offset the initial cost eventually.

The filtration unit and media you choose will depend on your personal preference and circumstances. Do your research then discuss the options with your pool company.

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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