Drinking water disinfection: How do I dose chlorine dioxide products correctly?

This simple and often asked question unfortunately has many answers and should be explained in more detail here. Chlorine dioxide eliminates bacteria, viruses, fungi, spores, algae, mites, parasites and biofilms very broadly and is considered the best germ killer in the world. There are different development stages of chlorine dioxide products with different advantages and disadvantages. These development stages are explained in more detail here:


The classic version - our MMS CLASSIC - consists of two components: A bottle of 25% sodium chlorite solution (component A) and a bottle of 4% hydrochloric acid (component B) as activator. By mixing both substances in a ratio of 1:1, the desired active ingredient chlorine dioxide is produced.  Here, the dosing is always done drop by drop during activation. Due to different droplet openings and temperatures, the droplet size can vary by up to 250%. This makes exact dosing of the classic version difficult. Extrapolating to larger quantities of water only increases this error. Therefore, dosing recommendations for the MMS CLASSIC are not further listed in the following tables

The rough rule of thumb: 3 activated drops of the MMS CLASSIC (to 150ml water) = 1 ml CDSpure / 1ml activated CDSplus

NOTE: The MMS CLASSIC is always dosed drop by drop during activation! Dosing is only possible very roughly!


With our CDSplus® you have one or more activation tablets and a liquid component (no water!) depending on the bottle size. After activation, you get a chlorine dioxide solution with a strength of almost 3,000 ppm. This can be precisely dosed in millilitres with a pipette or a dosing cup.

NOTE: CDSplus is always dosed exactly in millilitres (not in drops)!


Our CDSpure®, on the other hand, is a highly pure ready-to-use solution for direct use. No prior activation is necessary here.

NOTE: CDSplus is always dosed exactly in millilitres (not in drops)!

The dosage of activated CDSplus and ready-to-use CDSpure solution is therefore identical.

What is the maximum amount of drinking water I can sterilise with one chlorine dioxide product?

Although the radical effect of chlorine dioxide on germs is always the same, many countries have different legal requirements for dosage. Since the germ count is also higher at higher ambient temperatures, this can be explained by the geopraphical location of these countries.


The following table shows the maximum amount of water that can be disinfected for our different products CDSplus and CDSpure and the different dosage forms (all with just under 3,000 ppm chlorine dioxide concentration). The exposure time is always 20 minutes.

In France, for example, you are only allowed to disinfect up to 500 litres of water with a 100ml CDSpure bottle, whereas in Switzerland it is up to 6,000 litres. For this reason, we will always indicate the range 500 - 6,000 litres on the 100ml bottle in future. In future, we will orientate ourselves to the smallest and largest values in Europe. These specifications refer to drinking water disinfection and are listed in the left column (under the tap symbol).

Meine Tabelle
Tank size Chlorine dioxide amount
Liter ml
2,5 1,25
5 2,5
20 10
25 12,5
50 25
100 50
200 100
250 125
500 250
1.000 500
2.000 1.000

The picture serves as an example representation for 100ml CDSpure/CDSpure.*The right-hand column applies to shock or tank disinfection discussed below.

How many ml of chlorine dioxide solution (just under 3,000 ppm) do I need to sterilise x litres of water?

In practice, you know the amount of water you want to disinfect. The following table shows the required amount of chlorine dioxide solution.

Water volume CH DE / IT AT FR
Liter ml ml ml ml
1 0,02 0,07 0,13 0,20
2 0,03 0,13 0,27 0,40
3 0,05 0,20 0,40 0,60
4 0,07 0,27 0,53 0,80
5 0,08 0,33 0,67 1,00
6 0,10 0,40 0,80 1,20
7 0,12 0,47 0,93 1,40
8 0,13 0,53 1,07 1,60
9 0,15 0,60 1,20 1,80
10 0,17 0,67 1,33 2,00
20 0,33 1,33 2,67 4,00
30 0,50 2,00 4,00 6,00
40 0,67 2,67 5,33 8,00
50 0,83 3,33 6,67 10,00
100 1,67 6,67 13,33 20,00
200 3,33 13,33 26,67 40,00
300 5,00 20,00 40,00 60,00
400 6,67 26,67 53,33 80,00
500 8,33 33,33 66,67 100,00

Why are chlorine dioxide solutions overdosed in practice?

Most of the time, the degree of germ contamination of the water cannot be seen with the naked eye. A glass of water can contain from a few thousand to several million germs and still look clear. So without a fully equipped laboratory, the germ load can only be estimated. In addition, temperatures above 21 degrees Celsius can significantly shorten the effectiveness of the chlorine dioxide solution. To reliably exclude residual germ contamination, in practice the chlorine dioxide is often significantly overdosed. This can reach two to ten times the values given in the table. This has been proven to have no side effects on health. The active ingredient chlorine dioxide either decomposes into harmless water, oxygen and the smallest amount of common salt or escapes partially into the environment (outgassing). Therefore, especially with higher water quantities and doses, always work in well-ventilated rooms.

What is the shelf life of drinking water disinfected with chlorine dioxide?

Unfortunately, this question cannot be answered in general terms either. The shelf life depends on the ambient temperature, the degree of contamination of the environment and the number of times the product is removed from the vessel. The shelf life can therefore range from a few weeks to a few months or longer. The warmer and more microbialised the environment, the faster re-germination can occur. Frequent withdrawals also favour the outgassing of chlorine dioxide residues and the penetration of environmental germs and thus also shorten the shelf life.

Shock cleaning of tanks

The above information applies to the sterilisation of drinking water and assumes a clean or sterile vessel or tank. If water residues are left to stand for a long time in drinking water tanks, e.g. at the Caravon, this can lead to a strong formation of germs and algae. In this case, at least at the beginning of a new use, this tank and the pipes should be thoroughly sterilised. This shock cleaning requires a significantly higher dose of chlorine dioxide and a longer exposure time. For this intensive type of tank cleaning, there are only specifications according to the German Drinking Water Ordinance. There is no need to differentiate between individual European countries.

How do I carry out a drinking water tank cleaning?

The tank is filled to one third with water. Then add the amount of chlorine dioxide solution according to the following table and fill the tank completely. Open all tapping points briefly so that the solution reaches all pipes and taps. If possible, open all taps again briefly after 6 hours. The total exposure time should be 6-12 hours. Then empty the tank completely via the waste water tank. Rinsing is not necessary. The tank can now be filled with fresh water and preserved with the above dosages for drinking water disinfection. In case of very heavy contamination, repeat the procedure.

Tank size Chlorine dioxide amount
Liter ml
2,5 5
5 10
10 20
12,5 25
25 50
50 100
100 200
125 250
250 500
500 1.000
1.000 2.000

Note: The values given here are the result of an alignment of the specifications of individual European countries. Different values may still be stated on products from current stocks during the transitional period. In future, we will only use these values on our products.