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Water Filtration

Filtration of Fluoridated Water

This page has been written to help those people living in areas which are already fluoridated and who pay a fixed amount for their water charges. If you pay according to the amount of water you use (i.e. metered), see the discussion about R/O.

This is an update (17th April 2019) of the advice previously given on this page.

Previously it was thought that there are two effective under-the-sink methods of filtering fluoridated water: Reverse Osmosis (R/O) and Activated Alum. Both methods are convenient and affordable although it's necessary to factor in a plumber's charges.  However, some people have their doubts now about whether activated alum really does remove fluoride although when FADS analysed the product water a few years ago, the product water was relatively fluoride-free.  So it might be that US activated alum filters are made in a different way to UK activated alum filters. 

Whole-house filtration units are also available although we have no direct experience of these systems.

Electric water distillation units are also a good way to produce very pure water. 

Two other types of filters which remove fluoride are The Big Berkey/Berkefeld and Zero Water pitchers.  The latter is very new and we have only had one opportunity to analyse the product water so far.

Equipment which will not remove fluoride
Fluoride cannot be removed by using a filter jug system (such as Brita, EcoBud or AkalaQuell).  Nor does fluoride disappear when boiling the water.  

Be aware that any filter that seems too good to be true ought to avoided.  In this category are filters which give you alkaline water, filters which you can carry around with you, jug filters, water-softening systems, sediment filters and long column carbon filters.  (As noted above we have hopes of the Zero Water pitcher although it is a 'jug filter' system.)

Bone charcoal can reduce fluoride but these filters are not ideal for Moslems, Hindus, Sikhs, Jews, vegans and vegetarians.  Current advice is to use a carbon block as the first in-line filter to remove chlorine and then insert a bone charcoal filter as the 2nd in-line filter to remove much of the fluoride.  A third (ceramic) filter can also be added as the third in-line filter.  If intending to buy an assembly of the two or three filters, the manufacturer should be closely questioned regarding the filter unit's capacity to reduce fluoride.  The LINK takes you to a video which tells you more about carbon and bone charcoal.

A filtration equipment company has told us that if the water passes through the filter/s quite quickly, then the chances are that any fluoride is not going to be trapped.  To be on the safe side it would be better to assume that filter jugs DO NOT remove fluoride.

Boiling fluoridated tap water concentrates fluoride.  Using fluoridated water for making up baby formula is definitely NOTrecommended because baby will be overdosing on fluoride and if boiled there will marginally be even more fluoride in the formula. However, it is unlikely that any hydrofluoric acid will still be present in the baby formula because this fumes off at high temperatures.

Equipment which will remove fluoride
As mentioned above in the introduction, fluoride is removed by Reverse Osmosis Filtration Units (R/Os or ROFUs), possibly by Activated Alum and by distillation. Whole House Filtration systems are available in the UK for removing fluoride and this will mean that when taking a hot shower or bath, hydrofluoric acid is not absorbed through the skin.  However, we have not yet been able to analyse product water from UK whole-house systems and therefore cannot recommend any at this time. 

R/O filtration removes all minerals, injurious or beneficial, from the water and the volume of product water is enough for everyday use (but not for showering and bathing).  97% of the fluoride is removed when the filters are new.  Disadvantages: The product filtered water tastes 'flat' but an add-on unit can be purchased to add a small amount of minerals to the product water to improve its taste.   The unit wastes water (2.4 litres for every 1 litre of product water) so are not completely suitable for families with a water meter. When in use, water containing highish levels of minerals and contaminants constantly drip into the outside drain. (2nd Generation R/O units waste less water.) You may need to employ a plumber if you canít do D.I.Y. because a hole needs to be drilled through the edge of the sink for the tap.  (Filters and membranes are easier to fit.)  Manufacturers recommend replacement of filters and membrane every 6 months and every year respectively.  Again, this may not be necessary if your total dissolved solids (t.d.s.) gauge indicates that the t.d.s. level in the product water is quite low.  (We normally replace the filters if the t.d.s level is above 30.)  It is not inevitable that the membrane needs to be changed once a year if the product water flowing through new filters has a low t.d.s.  The flow of water from the special tap is slow.  R/O may not be permitted by the landlord if you live in rented accommodation.  Some R/O units use electricity during the day and this may increase your electricity bills. Whole house R/O systems are not available due to the slowness of producing the product water.  Advantages.  They're tucked away out of sight and you donít need to remember to fill them and switch them on.  Not all R/O units use electricity.  They are suitable when there are young children in the family.  The product water can be put in steam irons but not for making colloidal silver.

It is possible to rent R/O units.  

Two Reverse Osmosis Systems


Activated alum filtration

Not all chemical parameters (elements) are removed by the activated alum process and in-line filters are needed for each element which you wish to remove.  For example, if your Water Company's water quality report tells you that you have arsenic in your drinking water then you may wish to purchase an arsenic filter as well as a fluoride filter.  There may not be enough room under your sink if you wish to filter out many injurious chemicals.  Alum is short for aluminium and although the aluminium is 'fixed' as a component of a compound in the filter medium, caution is advisable here since it would be counter-productive to remove fluoride and yet allow aluminium fluoride to enter the product water. 

Bottled water 

It is advisable to supplement filtered 'flat' water with occasional glasses of bottled water.  

Most bottled waters produced in the UK are fortunately very low in natural calcium fluoride.

Some European Natural Mineral Waters (NMW) contain undesirable minerals so it's always best to read the label. Kirkland sold by Costco is now sourced from the Chase Spring near Lichfield and contains 0.1ppm fluoride whereas a few years ago Kirkland was a French water containing 1ppm fluoride. Parents with young children need to be particularly careful about the sodium and fluoride content although most mineral water available in the UK has lower levels of sodium and fluoride than is found in some of our tap water.  The exceptions are S.Pellegrino, Badoit and Volvic which are expensive and not beneficial to good health in the long term.

NMW from the Derbyshire Peak District is not recommended since it contains a little fluoride and/or uranium. (  

This website has a database which lists bottled water and fluoride content.  Not all NMW labels are correct regarding fluoride content.  The labelling of NMW is controlled by Trading Standards who have been contacted by WMAF in the past when an incorrect label has been discovered.  UK Law governing the sale of NMW is quite strict.  However, with financial cuts, Trading Standards is no longer able to investigate every case reported to them.  

Distillation of tap water is a good way of producing very pure water although clearing out the minerals and contaminants from the inside of the distiller unit is a pain.  Despite one researcher warning against drinking distilled water on a long-term basis, other researchers have found no long-term problems.  o improve palatability such 'flat-tasting' water can be improved by the addtion of a few drops of lemon juice or bicarbonate of soda.  

Distillation units offer a suitable back-up system while waiting for replacement R/O filters and membranes to be installed and the product water is ideal for making colloidal silver.  The units run for 4 hours so use a lot of electricity. They're less expensive to run if you have solar panels.

Big Berkey/Berkefeld.  This is a gravity filter housed in an imposing large stainless steel container.  It requires 4 filters, 2 of which have to be specified by the customer for the removal of fluoride.  The unit is free-standing and too large to be placed on the counter-top.  Thus, a stand needs to be purchased to provide clearance for the collecting vessel.  Beware of cheap clones when purchasing replacement filters.  It is recommended to only buy the filters from a recognised supplier.  The drawbacks: the unit has to be filled with tap water manually, possibly every night using a hose attached to the kitchen tap.  Since it's such a large unit, it would probably overcrowd a small kitchen.  The advantages are that the unit has no moving parts and has a long life.  Also, it's not plumbed-in and is therefore portable.  

                                    Quotation from entry in Wikipedia for Water Quality

"Drinking water or potable water is water of sufficiently high quality
that it can be consumed or used
without risk of immediate or long term harm."

Since the fluoride in fluoridated water causes harm and since the fluoridating acid contains arsenic (which is a carcinogen) and hydrofluoric acid, Severn Trent's and South Staffordshire's water is not of sufficiently high quality
and is therefore not potable....

... but just try getting the Department of Health to agree with you!