How much chlorine needs to be in the pool?

Having your own pool significantly enhances your garden as a recreational area. Not only in summer heat waves, it invites you to cool down, exercise and simply relax. Similar to public swimming pools, chlorine also ensures consistently good water quality here. We'll tell you here what amount of chlorine belongs in the pool water and how the perfect first filling works.

How much chlorine is there in the pool?

How exactly the right amount of chlorine should look like in the pool is difficult to say with a single value. There are two reasons:

Different manufacturer information

Every manufacturer of pools or pool accessories specifies their own value for the ideal chlorine content in the pool for their products. Although the values ​​are all in the similar range, they are seldom completely identical. If the current information is coincident, this results in a desirable value of around 0.6 to 1.0 mg chlorine per liter of pool water, in short, 0.6 - 1.0 mg / l.

The variance

The chlorine content of a pool is never constant, but steadily decreases over time. This means that you start with a slightly higher value and end at a value below the ideal value before the new chlorination. For this reason, information is often found for the first chlorination that is up to 3 mg / l above the averaged ideal value of around 1 mg / l.

Another reason for an initial overdose of chlorine can be the intention to carry out a so-called shock chlorination or shock disinfection. For more information, see the step-by-step instructions.
For the first filling of the pool you can either orientate yourself on the ideal chlorine content in the water, or consciously follow the slightly higher value for the first filling. Depending on the decision, the first post-chlorination may be necessary a little earlier, or the initially higher chlorine value for Particularly sensitive people may appear through a slightly more intense perception in the water.

Note: Even if you opt for a higher initial chlorination, the higher value does not result in any concerns with regard to the water tolerance for the bathers. This fixed upper limit does not result from an incipient danger from the chlorine content, but rather from the amount of chlorine required for the desired disinfection.

Chlorine content and pH

The pH value of the pool water is always directly related to the chlorine content of the pool. The desired amount of chlorine can be set independently of the pH value. The substance can only achieve the desired disinfecting effect within a very narrow range of the pH value. Ideally, this is between 7.0 and 7.4. If the control with the pH test strips shows deviating values, preparations for increasing or decreasing the value should be used before adding the chlorine according to the manufacturer's instructions.

Note: If you notice a clear smell of chlorine in the pool, too much of the substance is rarely the cause. Far more often, an incorrect pH value causes some of the chlorine to flocculate. It is precisely this unusual part that is then clearly perceptible by smell.

Chlorine preparation

The private pool market is growing all the time. The supply of necessary auxiliary materials is also growing, including chlorine. Chlorine tablets or pellets are common today, and less often fine granules or powder. All these products can be stored and used in a similar way if handled correctly. At this point, we clearly advise against liquid solutions or gaseous use. Both are almost not available on the free market for private use, since the dangers of incorrect use can be enormous.

First fill pool

Now that it is known how much chlorine is required per liter of pool water, the first chlorination can be implemented. This usually takes place as shock chlorination, i.e. as a one-time application of the entire amount into the pool. Subsequent post-chlorination, on the other hand, usually takes place via permanent long-term administration, for example via long-term granules with slow dissolution.
Step by step, this procedure leads to the correct chlorine content:

• Fill the pool completely before carrying out the first chlorination
• Determine the amount of water in liters - calculable from the length, width and depth of the pool
• Examination and if necessary Adjustment of the pH value for optimal effectiveness of the chlorine with pH increase or decrease
• Calculation of the required amount of chlorine (amount of chlorine in mg = pool volume in liters x chlorine content per liter of water)
• Determination of the absolutely necessary amount of chlorine by weighing or counting the chlorine tablets
• Variant 1: Dissolve the tablets in a separate bucket and pour the solution into different parts of the pool
• Variant 2: direct injection of the pellets into the pool, distributing the injection over the whole pool
• After waiting for complete dissolution and distribution in the pool water, check the chlorine content using test strips or a measuring device

Note: Many modern chlorine granules are suitable for being added directly to the pool. According to the manufacturer, other products should be dissolved in the bucket beforehand to avoid discoloration on the pool floor. Therefore, before using the chlorine, it is essential to consult the instructions for use of the selected product.

Shock chlorination

Again and again one reads about shock chlorination or shock chlorination in connection with the initial filling of pools. Shock chlorination. On the one hand, it is often used to describe the one-time and simultaneous administration of the entire amount of chlorine into the pool water. However, a different goal is actually pursued with shock chlorination:

To do this, not only is the entire amount of chlorine administered to the pool at once, but more than that also deliberately overdosed and thus a significantly increased chlorine content of up to 50 mg / l (!!!) achieved. The aim of this procedure is to prevent so-called chloramines. Chloramines, or combined chlorine, are compounds of chlorine and nitrogenous substances such as protein or urea. Before disinfection with chlorine, the water usually contains significantly higher proportions of these substances, as in water is the case with active chlorination. The resulting chloramines must therefore be expected to a greater extent the first time chlorine is administered. The result is the typical swimming pool smell, as well as the cloudiness of the water and the formation of white flakes.

Attention: After performing shock chlorination, you should not use the pool until the chlorine content has decreased to normal values! Otherwise eye and skin irritation as well as problems of the respiratory tract can result.