What is a Water Filter System?

How Does a Water Filter System Work?

The basic function of any water filtration system is to capture any sediment or particles and absorb or preclude potentially harmful substances from the water passing through it.

Why Do You Need a Water Filter?

Tap water in the UK is amongst the cleanest in the world but that doesn’t guarantee it will always look, smell or taste clean. Chlorine is added to mains tap water to keep it clean and clear of bacteria and germs and this can affect the taste and smell. Depending on where you live and hardness of your local water supply, limescale can become an issue, especially if it blocks pipes or forms in appliances causing inefficiencies and breakdowns in heating elements and boilers.

Naturally occurring fluoride can be found in some water supplies while lead and iron can be absorbed from the pipes running to your home. To avoid this, many people choose to drink bottled water though, as widely publicised, this has a profound environmental impact. Another option is a filter jug but these can be costly and sometimes fail to remove all the impurities which can be present in the municipal water supply.

In rare cases, harmful bacteria like E-coli and parasites such as cryptosporidium can be found in UK mains water. These can cause unpleasant and occasionally severe symptoms, though thankfully, these kinds of outbreaks don’t occur often.

What Types of Water Filter System Are There?

There are a number of basic methods of water filtration. Some systems use a single method while others use a combination of methods or media to achieve the desired effect.

Here we look at a number of the most common types of water filter systems for domestic use:

Under Sink Water Filters

Under-sink water filters can be fitted under domestic or commercial sinks. The filtration system is kept hidden from view and filtered water can be obtained either via an extra tap or from a 3 way tap.

There are a number of different types of under-sink water filter system, including:

The Water Gem

The Water Gem is Europe’s best selling DIY under-sink water filter system and is made in Britain from WRAS approved materials. This system comes with everything you need to tap into your mains water supply and comes with a tap of your choice.

Taste Great Drinking Water System

The Taste Great Drinking Water System has been designed to be easily installed without the need for a plumber. It improves the taste and odour of mains water by reducing chlorine and other chemicals which occur in mains water supplies using granular activated carbon or ceramic filters.

Doulton Water Filters

Doulton® water filters are ceramic and are capable of removing more than 99.99% of pathogenic bacteria and disease causing cysts and particles while allowing beneficial minerals to pass through. The outer shell on this product can be cleaned in order to prolong the life of the product.

Everpure Water Filters

Everpure filters are top end systems that cover a huge range of applications including foodservice, vending, coffee and ice machines. While used mainly for commercial applications, there are also Everpure filtration systems designed for domestic use, providing the same advanced technology in your kitchen.

Cryptosporidium Removal Systems

Andrew’s offer a range of cryptosporidium removal systems that are capable of removing the water-borne bug, which has seen several outbreaks in the UK recently. These systems remove unwanted contaminants similar to other filters but with micron ratings small enough to exclude cryptosporidium and other cysts.

Counter Top Water Filters

Counter top water filters are portable water systems which don’t require any plumbing or installation and are ideal for transporting to areas with unsanitary water conditions. A diverter pipe connects directly to a tap and routes water through a filter and out of the counter top system’s spout – simple but effective.

Water Filter Taps

Water filter taps are more premium items and replace the current faucet. 3-way filter taps suited for regular home use provide instant hot, cold and filtered water, providing an all-round solution for your domestic water requirements. Time and power-saving boiling water taps are perfectly suited for use where boiling water is required regularly.

Water Filter Housings

Water filter housings are durable protective casings that are built to house replaceable water filter cartridges. Various sizes and mounting options are available and we can also offer housings suitable for reverse osmosis membranes.

Calcium Treatment Units (CTUs)

Calcium Treatment Units or CTUs have been the industry standard for many years for reducing limescale and improving taste and odour in commercial foodservice and vending applications. CTUs utilise a de-alkalisation process and are suitable for use with coffee machines, combination ovens, baking ovens and water boilers.

Under Counter Chillers

Under counter water chillers supply cool, refrigerated water on demand using an electric cooling unit. Generally used more for commercial use, chillers can supply up to 12 litres of ice-cold filtered water an hour.

The Five Types of Filter

Mechanical Filters:

Mechanical filters use a barrier method to remove sediment, dirt or other harmful particles and typically use media made from carbon or ceramics. Particles removed are measured in microns - the smaller the micron rating of the filter, the fewer impurities will pass through with a rating of 0.5 microns being sufficient to stop harmful parasites such as Cryptosporidium.

Sequestration Filters:

Sequestration is the action of chemically isolating a substance. A commonly used sequestration media is polyphosphate which sequesters the calcium and magnesium which cause limescale and corrosion. However, polyphosphate inhibits scale rather than removing it which means that though it’s suitable for domestic use, it’s not suitable for commercial applications. (Incidentally, the small amount of polyphosphate inside the Water Gem means that if you fill your kettle up from your filter tap, you’ll see dramatically reduced scale build up.)

Ion Exchange Filters:

Ion exchange is the method of softening water by ‘swapping’ the ions that cause water to become hard. The filter enables the exchange of magnesium and calcium (two elements which cause limescale and corrosion) with ions such as sodium or hydrogen, which don’t form scale. Absorption Filters Absorption filters use a filter media, usually granular activated carbon (GAC) or a carbon block, which absorbs contaminants, improving the taste and odour of your water. Generally carbon block filters cost slightly more than GAC filters but they are better at filtering out particles and are usually micron rated.

Reverse Osmosis Filters:

Reverse osmosis refers to the process by which a solvent is pressurised to pass through a semipermeable membrane in the reverse direction to natural osmosis. This process pushes out pure water through the membrane while other molecules cannot fit through leaving the majority of dissolved contaminants behind. Reverse osmosis is a particularly thorough method and can result in water purity of up to 99.9%. However, there is a trade-off in terms of efficiency as most RO membranes produce a certain amount of waste water which must be sent to drain.

Not Sure Which Water Filter System Is Best For You?

We know it can be difficult to choose the correct water filter system with so many factors to consider. If you are unsure of anything or would like some advice on specifying a water treatment system, please contact us.