Consumption of Low TDS and pH Water


1. Misleading claims

There are many misconceptions regarding water with a low mineral content. Certain companies bottling mineral water or selling filter systems are exploiting this lack of knowledge for their own benefit. Uninformed people are easily bluffed by reading the mineral content on a bottled water label. People often think that minerals in water are very essential to human health without taking the Recommended Daily Allowance (RDA) into consideration.

I will illustrate that point with two examples. I refer you to the RDA of Dr Willem Serfontein.

Nutrient Old RDA
(persons 4 years and older)
(persons older than 10 years)
 Calcium  800 mg  800 mg
 Phosphorous  800 mg  800 mg
 Magnesium  400 mg  300 mg
 Iron  18 mg  14 mg
 Zink  15 mg  15 mg
 Iodine  150 μg  150 μg
 Copper  2 mg  not included

We will use two mineral waters on the market whose names will not be disclosed and name them Mineral Water 1 and Mineral Water 2.

Mineral Water 1

The label states that the calcium and magnesium content of Mineral Water 1 is 6 mg/L for calcium and 3mg/L for magnesium. According to the RDA our calcium intake should be 800 mg/L and that of magnesium 300 mg/L per day. A simple calculation will show that we will need to drink 133 litres per day to achieve the RDA.

Mineral Water 2

According to Mineral Water 2’s analysis, the calcium content is 2,5 mg/l and the magnesium content 3,7.  If we do the same calculation, and compare it with the RDA, we need to drink 320 litres of this water every day to comply with the calcium intake!!
These two examples emphasise the fact that vital mineral and vitamin intake come from the food we consume and not from water. Water contains no vitamins. Pure water is needed to transport essential nutrients and vitamins in the body and is not a source of food.

2. The Russian Report on Mineral Intake

In the report Health Risks from drinking Demineralised Water in 1980 the World Health Organization quotes a study done by two Russian scientists, G.I. Sidorenko and Y.A. Rachmanin (Guidelines on Health Aspects of Water Desalination) on drinking water with a low mineral content. This was an isolated report2 which was not followed up with further studies to confirm their findings. The Russian studies, as reported in Annex 8 of the WHO document appeared not to be rigorously scientific.3
This report is only six and a half pages long.

The WQA reports that a search was done for 12 months to find any credible literature on the subject of consuming low TDS water. The result was that very little information is available in western scientific literature relating to the physiological effects on the human body of consuming low TDS water.4

The Russian report was intensively reviewed by Dr. Lee Rozelle and Dr. Ronald L. Wathen. Dr Rozelle summarised as follows: The data for their conclusions, summarized in Annex 8 of the WHO unofficialguidelines, are not very convincing from a scientific viewpoint. The conclusion of a minimum TDS of 100 mg/L is confusing and not very convincing.5

Dr. Wathen wrote the following commentary on the report: The Annex VIII of the report is an alleged “review” of water and salt balance under the influence of a variety of water and salt intakes, in a variety of animals, including humans, exposed to a variety of conditions. The review is long on deductions, but very short on (re)presentation of solid data. Moreover, probably only a handful of references cited in this review (assuming they are cited correctly) may be from credible scientific journals, that is, journals which demand proper scientific methodology and peer review of all work, prior to publication. Many of the cited articles may be from journals of “personal opinion”: being versed only in English, it is impossible for me to establish the credibility of the cited work.6

On page 7 of the WQA report Dr. Wathen says: Salts and minerals are not “leached” out from the human body; they are preferentially retained or excreted, either of these events occurring relative to whether or not one is surfeit in water or salt or both. In short, the human body is not a lead or copper pipe which “leaches” in the presence of purified water. The Annex VIII review is very misleading in this regard.

The low TDS water is often combined with other substances such as coffee, tea, fruit juices and other drinks which we all know, enhances the taste, But, Dr Wathen continuous, even if the TDS is not raised by some external means, through the addition of saliva, gastric secretions, and small intestine secretions beyond the stomach, there is an internal elevation of in TDS of any dilute fluid one might drink. It would be my opinion that the adsorptive portion of the GI tract, that is, the small intestine, in the absence of extreme water loading, never sees a hypotonic solution sufficient to cause the mucosal cells to swell or to appear damaged. There is a tendency in this review to draw conclusions from observations in anhidrotic 3 (non-sweating) laboratory animals (dogs, rats and rabbits) and apply them to the very hidrotic (sweating) human.7

The human body has an excellent way of controlling electrolytes and adjusting pH. The process of regulating electrolyte balance in the body is called homeostasis. This controls the mineral (ion) and water concentrations in the body fluids within narrow limits inside and outside all the cells. The kidneys are the most important organs maintaining constant ion concentrations through elimination and reabsorption.

  1. Definition of homeostasis:
    The ability or tendency of an organism or cell to maintain internal equilibrium by adjusting its physiological processes.8
  2. In physiology the metabolic equilibrium actively maintained by several complex biological mechanisms that operate via the autonomic nervous system to offset disrupting changes.9

The Canadian Water Quality Association reports: Fortunately, there is considerable evidence to counter the Soviet Studies. Dr Daniel Mentzel one of the nation’s leading toxicologists and the chairman of the University of California in Irvine, points to homeostasis as one of the reasons that the idea of leaching of minerals by consuming high purity water is an “erroneous assumption”. 10

It is true that the body needs minerals. However, your body is not dependant on minerals from water. For a mineral to be useful to the body it must be in a form in which it can be taken up by its matching enzyme. There is only one way a mineral can be utilized by an enzyme:, says Dr Ron Kennedy, and that is when it is delivered to its enzyme by an organic molecule.11 When a mineral is in such an association with a organic molecule, it is said to be chelated.

In his informative book New Nutrition, Dr Willem Serfontein cautions: Heavy metals, like lead, mercury and cadmium in drinking water is another source of contamination that should be avoided as much as possible by using only suitably purified drinking water. The subject of chemical pollution from the environment and its health consequences is a vast one and not many of us appreciate its significance.12

3. More evidence

  • WQA received the following responses from different experts in different fields: WHO’s Dr. Galal-Gorchev states that WHO (World Health Organization) has “no information that such (low TDS) water would have an adverse effect on mineral balance. U.S. EPA’s
  • Dr. Edward V. Ohanian, Chief of Human Risk Assessment Branch wrote: Drinking water supplies a number of minerals that are important to human health. However, drinking water is normally a minor source of these minerals. Typically, the diet is the major source of these beneficial minerals. I am not aware of any data adequate to support the conclusion that water with low levels of minerals is unsafe.
  • The U.S. Navy has used distilled water with less than three ppm TDS aboard ships for more than 40 years. Surface ships while on shore take on water from shore sources, but it is common for submarines to provide nothing but purified water for months at a time, all with no reported ill effects. This was confirmed with separate sources at the David Taylor Research Center in Annapolis, the Naval Sea Systems Command, the Bureau of Medicine and Surgery, and the Navy Environment Health Center. Finally, the Surgeon General directed the Navy to address the subject formally in 1972. The conclusion was that drinking distilled water is not harmful.

Minerals in Food vs. Minerals13 in Water

Compare the RDA of minerals (mg/100mg) in fruit, vegetables and nuts to those in water.

Vegetable Calcium Magnesium Potassium Iron
 Artichoke  53  22  353 1,5
 Broccoli  100 18  340  1,5
 Brussels Sprouts  30  20  382 0,6
 Cabbage 75  12  300 1
 Carrots  29  7  218 0,4
 Leeks  60 10  250 1
 Spinach  125  48 400 1,2
 Baby marrows  30 6 200 2,4
Nut/Seed Calcium Magnesium Potassium Iron
 Almonds 75 76 200 1,05
 Brazil nuts 45 107 187 0,69
 Cashew nuts 10 83 187 1,89
 Hazelnuts 32 46 193 1,33
 Macadamias 24 37 104 1,05
 Oats 54 177 429 4,72
 Sesame seeds 88 32 42 1,31
 Pistachios 31 34 295 1,19

There are also essential trace elements in vegetables as well as vitamins not found in water.

4. Conclusion

The Water Quality Report quotes some field experiences to demonstrate that there are no known documented experiences which show that consuming low TDS water will create any long-term health effects.14 These experiences include the following:

  • The US Navy has used distilled sea water for human consumption for approximately 40 years. TDS levels below 3 mg/L have been reported and consumption of this water for months at a time is common on submarines. No health problems have been reported by the Navy and they feel low TDS water is safe to drink.
  • The US Army uses reverse osmosis units to provide drinking water for soldiers in the field. They do not consider low TDS water to be a problem and have no minimum standard.
  • The US EPA conducted a project in San Ysidro, New Mexico in which the TDS was dropped from 800 mg/L to a range of 30 – 70 milligrams per liter. No health effects were observed during the one year test.
  • NASA has reported no ill effects from the consumption of approximately .05 mg/L TDS water on board space craft. It appears that the possibility that this could have been a problem was never seriously considered by NASA.

pH and Drinking Water

A question often asked is what is the effect of water, with a pH lower than 7, on human health? Under certain conditions a reverse osmosis purifier will lower the pH of the permeate or purified water slightly . (This depends on the equilibrium relationship between CO2, HCO3, and CO3). To understand the effect of pH on water, it is necessary to understand the following: There are strong acids and weak acids, and strong alkalis and weak alkalis.

The pH reading is not indicative of how strong an acid or alkali is, and cannot give any indication of the water quality. Strong acids and alkalis are corrosive, while weak acids and alkalis are non-corrosive. In water an acid or alkali is usually diluted. The pH of stomach juice, which contains hydrochloric acid is between 1 and 3, while commonly used foods like lemon juice and vinegar also have a low pH. They are weak acids though, and pose no health threat to humans or animals. The same applies to carbonated drinks which have a pH between 2 and 4, black coffee with a pH of 5, etc. Millions of people drink these beverages every day.

pH plays an important role in water treatment plants. Water with a low pH has a corrosive effect on metal pipes. It can leach metals like iron, manganese copper and zinc from the plumbing. This can result in water containing high toxic metals, and staining of bathroom and toilet fittings.

Water with a high pH may indicate water which is hard (containing high calcium and magnesium salts) and could form scale which may block pipes, resulting in decreased water flow and the clogging of geyser elements. It can also give water an alkali taste and is bitter when used to make coffee. pH also influences the effectiveness of water disinfectants like chlorine. For chlorine to disinfect effectively the pH must be under 8.

Water with a low pH poses no health threat to humans or animals. Various experiments have been performed to prove this. See De Zuane, J (1990). Handbook of Drinking Water Quality: Standard sand Control. Van Nostrand Reinhold, New York.

Many farmers acidify drinking water to protect their flocks from bacteria. Acidification is also used in laboratories to prevent bacterial contamination among laboratory animals.

The EPA (Environmental Protection Agency) and SANS 241: 2006 Water Standards shed more light on pH. The EPA does not regulate pH. It is classified under the Secondary Maximum Contaminant Levels (SMCL) which is regarded as aesthetic. The EPA recommends water that should have a pH between 6,5 and 8,5.

On pH WHO says: A direct relationship between human health and the pH of drinking-water is impossible to ascertain, because pH is so closely associated with other aspects of water quality, and acids and alkalis are weak and usually very dilute. However, because pH can affect the degree of corrosion of metals aswell as disinfection efficiency, any effect on health is likely to be indirect and due to increased ingestion of metals from plumbing and pipes or inadequate disinfection.

A quote from SANS 241: 2006 on pH: pH: No primary health effect – low pH values can result in structural problems in the distribution system.

Finally: The US EPA15 has recognised membrane processes such as Reverse Osmosis as a ‘best available technology’ (BAT) for meeting a wide variety of the Safe Drinking Water Act (SDWA) regulations.16


  • Wellcare® information for you about pH in Drinking Water.
  • Wikipedia.
  • Free Drinking Water:
  • Government of Saskatchewan: SaskH2
  • Wilkes University Centre for Environmental Quality:
  • SANS 241: 2006
  • World Health Organization: pH in Drinking-water. Revised background document for development of
  • WHO Guidelines for Drinking-water Quality.

1 Serfontein W (2001). New Nutrition. Tafelberg Publishers, Cape Town, p341.
2 Clean Water: When it is muddied by Misinformation, a study of the Canadian Water Quality Association reports: WHOreleased an unofficial summary of the article (without additional research or follow-up) in 1980 entitled “Guidelines on Health Aspects of Water Desalination by G. I. Sidorenko and Y. A. Rachmanin.
3 Dr Rozelee, L. T. and Dr Wathen, R. L. (1993). Consumption of low TDS Water. A committee report by Water Quality
Association Science Advisory Committee. WQA Technical Services.
4 Dr Rozelee, L. T. and Dr Wathen, R. L. (1993), p5.
5 Dr Rozelee, L. T. and Dr Wathen, R. L. (1993), p. 6.
6 Dr Rozelee, L. T. and Dr Wathen, R. L. (1993), p.6.
7 Dr Rozelee, L. T. and Dr Wathen, R. L. (1993), 7-8.
10 Clean Water: When it is muddied by Misinformation, a study of the Canadian Water Quality Association, p. 2.
11 Internet: The Doctors’ Medical Library, Dr Ron Kennedy, M.D., Santa Rosa, California.
12 Serfontein W (2001), p. 196.
14 Dr Rozelee, L. T. and Dr Wathen, R. L. (1993), p. 10.
15 USA Environmental Protection Agency
16 Water Conditioning & Purification Magazine International, February 2009