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Water filtration system buying guide

Guide written by:
Jeremy, construction site supervisor, Cardiff

Jeremy, construction site supervisor, Cardiff

118 guides
There's only one solution to improve the quality of your water, whether it's from a rainwater collector, mains supply or well... Filtration. With anti-limescale, sediment, magnetic, activated charcoal and cartridge filters on offer, household water filtration is a fluid topic!

Important features

  • Polyphosphate
  • Magnetic
  • Active carbon
  • Sediment
  • Cartridge

Why install a water filtration system?

Before going into detail, it's important to bear in mind that setting up a water filtration system doesn't change whether a particular source of water is classed as potable (drinkable) or not. The kind of filtration we're talking about here is not effective for disinfecting contaminated water sources.
Let's look at the various scenarios where you might want to install a water filtration system.

Drinking water filtration

Whether your drinking water comes from the mains supply, a private well or a collector, you might want to modify certain chemical parameters to improve its quality. This can be for your own health or to protect your home appliances or heating system. The most common type of filtration is to eliminate (or at least limit) limescale. Any suspended solids can also be removed by this process provided the correct type of filter is used.

Rainwater filtration

From a rainwater collector or pond, collected water can be pumped to power a toilet flush or pressure washer. In either case, the water must be cleared of any suspended matter it contains. Filtration is the ideal solution.

Rainwater harvesting is becoming increasingly popular given the rising cost of water. If you're collecting rainwater for sanitary purposes (flushing, washing, watering), installing a water filtration system is essential to protect your installation and equipment.

What different types of water filters are there?

There are a multitude of types of filters on the market, so we'll limit our discussion to the most commonly used types for a range of everyday purposes.

Cartridge filters

These provide conventional filtering without any active chemical processing, i.e. purely mechanical filtration. Capable of trapping suspended particles, cartridge filters are useful for reducing water turbidity (cloudiness). Filtration capacity is adjustable according to the size of the material you want to capture; just choose the most appropriate filtering diameter of cartridge. This varies from 5 to 100µm (microns). Cartridge filters are suitable for a wide variety of uses, from trapping grit present in a rainwater collector to filtering out microparticles at the supply point of the domestic water network. Often washable, cartridge filters must be replaced periodically. The most durable type are wound filters.


Polyphosphate filters

This type of filtration incorporates an active compound to limit or even eliminate the presence of tartar. Very useful for preventing scaling of pipes and sanitary installations. Polyphosphate filters can either be installed at the head of the network (after your water meter) or before specific appliances (for example at the water heater supply). Polyphosphates act chemically on the various scaling compounds, preventing solid deposits from forming. Depending on water consumption and the filter capacity, the active compound must be recharged once or twice a year. Polyphosphate filters may come in the form of cartridges as above.

Magnetic filters

Like the polyphosphates, magnetic filters make it possible to limit or eliminate tartar and limescale via the action of magnetic waves. The principle is essentially the same as above; chemical bonds are modified not by reaction with an additive but instead by the change of polarity of certain particles. Magnetic filters have the advantage of not using consumables (or indeed energy, for permanent magnet models). On the other hand, they are less efficient than polyphosphate filters. They are discreet and easily to install in a kitchen setting.


Active carbon filters

Advanced domestic water filtration intended to remove or reduce the presence of certain chemicals in your water. Active carbon can also reduce turbidity to some extent, as well as levels of some heavy metals. If you find that the water from your taps has a chlorine taste, an active carbon filter is the solution to neutralize the taste. Positioned at the water supply point, these are often combined with pre-filters to reduce clogging of the carbon elements, hence prolonging their lifetime. Factor in carbon replacement at least once a year as a rule.

Sediment filters

Also called pre-filters. The purpose of a sediment filter is to protect the filter downstream of it by trapping the larger suspended materials. In most cases, filtration capacity is around 20µm. Positioned at the water supply point, just after the meter, they limit clogging of cartridge or active carbon filters, prolonging their lifetime and limiting maintenance.

Water filtration: necessary maintenance

Whatever type of filtration you choose, the aim is to improve water quality. Note that a poorly maintained filtration system doesn't just fail to fulfil its role; even worse, it can degrade the quality of the water flowing through it!
If you've installed a water filtration device, be vigilant and uncompromising about maintenance required for your installation.

Change your filters as required, check and recharge consumables regularly if necessary, and if using cartridge filters, periodically clean your cartridges.
A well-maintained water filtration system is an effective one!

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Guide written by:

Jeremy, construction site supervisor, Cardiff 118 guides écrits

Jeremy, construction site supervisor, Cardiff

I'm a trained electrician who started off working in large-scale industrial projects. Most of my early career was spent taking on huge electrical installations. I like to think that no job is too big for me, and after all the experience I'd gained, I started managing teams of electricians.

I like to learn on the job, so around ten years ago, I moved into building and construction. As a site manager, I've overseen the building of small residences, sport facilities, and even theatres!

Working with my hands is something I love to do in my free time as well. For four years now, I've been restoring our home in the Welsh countryside. I even built a conservatory for my wife, who loves watching the sheep behind our house.

Whether it's patios, interior design, roofing, plumbing or electricity - I love giving it all a go! I've even made my family DIY converts and together we've built almost everything we have from scratch. My experience, both in the field and in my workshop, has taught me a lot and I'm happy to share what I've learned. No matter how big or small your project is, I'm here to answer your questions and help you choose the right tools and equipment.

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