What are Filter Taps?
What does a water filter do? How does it work? When you know the answers to these questions you can understand why more and more people are buying them.
Filtering water has been a human habit for about 6000 years. First we filtered water through fibres to clear the cloudy-ness of muddy streams and we have evolved now to using advanced technology to rid ourselves of all sorts of microbes and other impurities.
Why Would You Want to Filter Water?
These days our drinking water is treated so well that the bacteria it contains is minimal. There is however, a price to pay for this. The chemicals used to keep the water bug free can sometimes leave a taste very far removed from crystal clear water.
This is why you see so many people wandering around with bottled water these days. Thirty years ago people would have laughed at the idea of buying water in bottles until we started to realise what was in it!
Types of Water Filter
Charcoal and Carbon Water Filters
Most water filters today use what is called activated charcoal. Activated charcoal is charcoal, which itself is mostly carbon, that has been through chemical processes to make it soak up more water. When purchasing a filter of this type you will need to make sure that it uses activated charcoal.
Additionally, you will also have to change the filter on a regular basis to ensure that it maintains peak performance.
The water is absorbed into the charcoal which retains the impurities and pure water passes out the other end. Charcoal filters are just one kind of filter but they are not the be all and end all. Charcoal filters will absorb most of the impurities found in drinking water but they will not remove lead and copper.
If you are thinking about installing one of these units it has to be said that it is not the most cost-effective solution due to the changing of filters and also many people have found that storing a covered jug of water in the fridge is almost as good in terms of refining the taste.
Reverse Osmosis Water Filters
Another type of filter is an osmosis unit, or rather a reverse osmosis unit. This involves a great deal of water being pushed, or pumped, through a very very fine membrane removing a great deal of dissolved solids that exist in the water. It not only separates the bacteria etc…. but it separates some of the water too.
This water is wasted (some estimate between 20 – 30%) so reverse osmosis filters are not really an option for any domestic situation as.
This particular type of filter also changes the physical properties of tap water and due to this many have deemed it unfit for drinking or other domestic uses. If it is to be used for drinking or cooking in the home then additional steps have to be taken to add back into the water certain minerals that are removed.
Installing this type of filter also has another downside – The pressure of the incoming water flow is significantly reduced.
You might be thinking if it can’t be used in a domestic situation then where can it be used? Well, this particular type of filter is ideal for use in places where removal of the heavier particles is key making it ideal for hydroponic gowning setups and photographic development.
Ion Exchange Water Filters
Another filter system is called ion exchange and involves a chemical process within the filter which exchanges filter ions with the natural ions in the water which contain minerals and salts. In most situations sodium is used to replace the magnesium and calcium in the water.
Removing, or neutralising these salts and minerals has the effect of softening the water and reducing the build up of limescale making them great for use in hot water systems and domestic appliances such as washing machines and dishwashers increasing efficiency and also the longevity of the system or appliance in question.
Ion exchange filters do not work however when there is a lot of iron in the water.
Again, as with reverse osmosis systems it is recommended that any water filtered by this method is not used for drinking or cooking due to the higher levels of sodium and the potential health risks this can bring.
What Type of Water Filter Tap Should I Use?
In respect to the points above, choosing a filter really depends on the water you have and more importantly, what you are going to use it for e.g. not for human consumption.
For best results telephone your water supplier and ask for the results of their latest analysis. This will give you a better idea of the best kind of filter for you.
Installing a Water Filter Tap
Next is how you install it – all filters have a cartridge and most are charcoal based (if being used to supply drinking water).
You can exchange your kitchen tap with a 3 way tap seen in the image at the top of this page. This will give you hot and cold water as normal, then a third lever is connected to a water filter which is installed under the sink.
See our project on changing taps to install the unit and use the manufacturers instructions to connect the filter.
A water filter can also be installed "stand alone" (see the image under charcoal and carbon water filters).
These very often mean drilling the sink unit or worktop to install and you can get instruction on how to do this, and fix the tap, from our project on instant boiling water taps.
When it comes to plumbing the unit in – this is normally just a matter of tapping into the cold water feed but depending on the system you have chosen and the manufacturer will depend on exactly how this is done. To these ends pretty much all filter kits will come with their own installation instructions.
All project content written and produced by Mike Edwards