How to determine water hardness at home

Hardness in Drinking-water is called hard. Background document for development of WHO Guidelines for Drinking-water Quality / WHO water with a high content of mineral salts, mainly calcium and magnesium. Salts precipitate easily and build up plaque.

This build-up makes it difficult for household appliances, such as dishwashers or washing machines, to operate and may even break them. And because of it, snow-white bathtubs and sinks quickly turn yellow, and the chrome-plated surface of the mixers is covered with ugly stains.

The most reliable way to find out how hard water is flowing from your tap is to send a sample tube of liquid for laboratory testing. You can find out the addresses of the laboratories in the referral service of your regional Vodokanal division.

But the hardness of the water is also determined independently. Here are four quick and easy ways to do it.

1. Try the test strips

What is needed

• Test strips for determining water hardness. You can buy them at pet stores and appliance retailers. Alternatively, strips for determining the acid-base level (pH) of a liquid.
• Cup.

What to do

Pour the water you want to measure the hardness into a glass. Dip a paper test strip with reagent squares on it into the liquid.

Remove the strip and wait about a minute (the exact duration is indicated in the instructions). Under the influence of mineral salts, a chemical reaction begins and the color of the test squares will change.

To determine the hardness of the water, compare the color in the indicator windows with the sample in the instructions.

If you are using pH strips, remember the general rule: the harder the water, the more alkaline it is, that is, the higher the pH value. As a rule, soft water has a pH of less than 7, hard water above pH Levels in Drinking Water / ATS Environmental 8.5.

2. Buy a salt meter

This gadget has two electrodes that must be immersed in water. The electrodes create a flow of electrons and record the electrical conductivity of the liquid, which is closely related to the amount of magnesium and calcium salts.

What is needed

• Saline meter.
• A glass or any other container.

What to do

Pour the water, the hardness of which you want to measure, into a glass, and lower the salt meter electrodes into it.

The device will convert the electrical conductivity of the liquid into the units of water hardness accepted in a particular country, and show the result on the screen.

In the Russian Federation, the unit of measurement is the so-called degree of hardness (° F), which is also 1 mg-eq / l. Salt meters certified in the Russian Federation work in this system.

The hardness of the water is considered to be hard. Soft water. Hard water. Conversion of units (degrees) of water hardness. Water hardness standards. Tables of water hardness values. Water softening. How to remove water hardness / Engineering Handbook. Tables DPVA.ru water with an indicator of more than 10 ° J. A value from 2 to 10 ° W corresponds to medium hard water.

3. Use laundry soap

This method is based on one of the key features of hard water: Hardness in Drinking-water is poor. Background document for development of WHO Guidelines for Drinking-water Quality / WHO lathers are produced. It will require a little chemistry experiment.

What is needed

• Laundry soap.
• Grater.
• Electronic kitchen scales.
• Tea spoon.
• Distilled water. You can buy it at hardware stores or gas stations.
• Tumbler.
• Ruler.
• Measuring glass with a capacity of 1 liter or a liter jar.

What to do

Grate a little of the laundry soap on a grater and measure exactly 1 g on the scales.

Place the soap in a glass and add 3-4 tablespoons of warmed distilled water. Gently, so as not to form a lot of foam, stir until completely dissolved.

Then, using a ruler, add distilled water to a height (in millimeters) equal to the percentage of fatty acids in the soap. For example, if you took a standard soap labeled 72%, the height of the water in the glass should be 72 mm. Keep in mind that the glass pan also has a certain thickness, so measure the water column from the bottom, not from the table surface.

Stir the soap solution gently again. Remove foam gently if it has formed. Now there is so much soap in every centimeter of water column to bind all the hardness salts in 1 liter of distilled water, if their concentration is 1 ° dH (German degree of hardness).

Pour 0.5 liters of cold tap water into a measuring cup or jar. Pour soap solution into the container in a thin stream and stir gently until you notice that a stable white foam has formed on the surface of the liquid. Its appearance means that the soap has completely bound the hardness salts.

Measure the height of the remaining soap solution in the glass and subtract it from the original height. So you find out how many centimeters of solution were poured into a measuring container.

Each centimeter of the poured solution bound the amount of hardness salts corresponding to 2 ° dH in half a liter of tap water. This means that if, for example, 6 cm of solution had to be poured out to create foam, the hardness of the tap water is 12 ° dH.

To convert German degrees to those used in the Russian Federation, you can use the online calculator Water hardness calculator / Mosvodokanal on the Mosvodokanal website. 12 ° dH = 4.3 ° F, which corresponds to medium hard water.

4. Use a mirror

This method will allow you to guess how hard the water is flowing from the tap. But it will not give a specific meaning.

What is needed

• Mirror.
• Pipette.
• Distilled or boiled water.

What to do

Using a pipette, apply a drop of distilled and tap water onto a horizontal mirror surface. Wait for the liquid to evaporate. And then analyze the two specks with sediment remaining on the glass.

The more saturated the sediment from tap water, the more it differs from the almost imperceptible trace of distilled water, the higher the hardness.