Why is the water balance of the swimming pool important? Th, pH and TAC

The balance of the pool water is an essential issue, both for the pool and its equipment, but also for the bathers. It is defined based on 3 values ​​which are the TH (hydrometric content), pH (hydrogen potential) and TAC (full alkalimetric strength).

Keeping your pool water in balance helps protect your pool and its equipment from premature deterioration. In fact, poorly balanced water (too soft or too acidic) will end up causing problems with limescale deposits or rapid corrosion of the system.

The performance of your equipment (filtration, eco-sterilizer, heat pump, etc.) and the health of your pool are therefore closely linked to the balance of the pool water.

How hard is my pool water?

The hardness of water is defined by its value TH (Hydrothymetric titer)that is, from its load of calcium and magnesium salts. This process occurs when rain infiltrates the soil and becomes loaded with different minerals.

The more minerals the water contains, the higher its water content will be and therefore the water will be hard. The less it will be loaded with minerals and above all it will be soft.

With a multitude of soil types: calcareous, clayey, sandy or acidic, French municipalities therefore have water with very variable mineral loads.

In France, the North, East and South-East regions are known to have predominantly hard water. In contrast, the central and western regions have water described as soft.

The measurement of water hardness is expressed in French degrees (° f) or in mg/l: 1° f = 10 mg/l. Ideally, the TH must be between 10 (100 mg/l) and 25 °F (250 mg/l).

You can consult the various water data of your municipality directly on the website https://solidarites-sante.gouv.fr/sante-et-environnement/eaux/eau

What are the risks of water that is too hard or too soft?

• Hard water causes limescale deposits and encrustations in the pipes and pool equipment. It promotes cloudy water problems and leaves white lines in the pool.
• Fresh water contrary to what the name suggests, it will be aggressive. It causes corrosion of the system and affects the skin and eyes of swimmers.

How to correct the TH of your pool water?

Using a limescale remover it will allow you to prevent limescale deposits and encrustations on your equipment and in the pipes. However, these products do not remove the limescale present in the water, but agglomerate it. You will therefore have to use a pool robot or a vacuum cleaner to eliminate and repel them. You will also need pH Plus or Minus to adjust the pH level.

If the water in your area is too soft, you can treat it with a treatment based on hypochlorite orold a TH enhancer. They add calcium to the water to make it less corrosive. It will be used as soon as the pool is full.

Read our article: The 5 rules for keeping water crystal clear

Why is the pH of water important?

THE pH o Potential of hydrogen it is the value that allows you to determine whether the water is basic or acidic. Its value varies on a scale from 1 to 14. The lower the pH, the more acidic it is, the higher it is, the more basic it will be.

Like TH, pH is an important value for the balance of pool water. Its value, whether basic or acidic, plays a direct role on the condition of your pool, its equipment and bathers.

The ideal pH for pool water shouldbe between 7.0 and 7.4.

How is the pH of water measured?

The pH of your pool water is measured once a week, and there are mainly two ways to test the pH of your pool water.

• Or using test strips that, when immersed in water, will change color and tell you the pH value.

• Or using an electronic pH analyzer. We recommend using an electrical analyzer as it is more accurate than a test strip.

You will also find tablets and liquid reagents for pH analysis. However, they are more restrictive to use, because they require more management.

What are the risks of an unbalanced pH?

• A basic pH : basic water such as high TH water increases limescale deposits and the risk of encrustations in appliances and pipes. The high pH also promotes cloudy water problems and makes disinfectant products ineffective.

• An acidic pH : Acidic water causes corrosion of your equipment and affects the health of swimmers. Irritation of the eyes and mucous membranes are also signs that should alert you.

pH is a value that changes rapidly depending on many factors. Storm, rain, frequency of bathing, number of bathers, chemicals, etc., are all causes that influence the pH value. Don’t hesitate to test during periods of extreme heat.

How to adjust the pH of swimming pool water?

In powder, pearls or liquid, you will find products called pH less and pH more which allow you to increase or reduce the pH of your water.

TAC, the “buffer power” to stabilize the pH

The TAC or Complete Alkalimetric Title that is, the alkalinity of water is a measurement that allows us to define the concentration of minerals, i.e. bicarbonates and hydrogen carbonates in water. Less known than pH, TAC is however an equally important value for water balance.

Why is this so important? TAC is the element that limits pH variations and stabilizes it. It therefore plays a buffer role and its value is directly linked to the pH. Therefore, if you notice any unusual changes in pH, remember to check the TAC value.

How to measure the TAC of your pool water?

The TAC value is measured using test strips or electronic devices such as a photometer.

The ideal TAC should range between 8°f and 14°f i.e. between 80 mg/l and 140 mg/l have optimal buffering power.

Like TH, its value depends on the region you live in, which is why it is important to measure its value as soon as the pool is filled with water.

What are the risks of a bad CT scan?

The closeness of the relationship between TAC and pH implies substantially identical risks.

Like pH, a bad TAC will have a direct influence on your pool and its equipment. Limescale deposits, pipe scaling and equipment corrosion when the TAC is low. Note that a very low TAC makes pH control difficult.

How to adjust the TAC of the pool water?

As we have seen, TAC and pH share a close relationship and the slightest change in one causes a change in the other. This is why it is important to analyze all the values ​​of your water before carrying out any water balancing.

For example, if the pH is bad, you must first analyze the TAC and determine its value. If it is bad, you need to correct it first before correcting the pH.

• If the TAC is too low, less than 10°F: use sodium bicarbonate or TAC+ (e.g. Alkanal POUDRE de HTH®)
• If the TAC is too high, above 30°F : use pH Minus which will also lower the TAC. The challenge will be to release the carbon dioxide contained in the sodium bicarbonate. A natural way would be to create vortices in the pool: water fountain, waterfalls, bathers, etc. In any case, the rectification must be carried out gradually and not suddenly. To leave the chemicals working and not further unbalance the pool water.