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Every swimming pool has to be filled at least once. But over time, you will likely need to refill the pool at some point.

To ensure that this does not have to happen too often, or at all, it is important to counteract the pollution of the pool with the help of effective pool care.

In addition to chemical agents, physical measures are also suitable for this purpose, which keep the water of the pool not only visually, but also hygienically in a perfect condition.

In addition to the regular supply of fresh pool water, this also includes the complete change of the same, whereby there are some factors to consider, which are explained in the following sections.

When should the pool water be changed?

Although it is highly recommended to operate the respective filtration system on a daily basis during the pool season, adjusting it to both the frequency of pool use and individual weather conditions, among other factors, this alone is not sufficient to ensure adequate water hygiene, which could lead to dangerous diseases.

In addition, e.g. the disinfection of the pool water with chlorine, which takes place at certain intervals, as well as other chemical adjustments of the water properties are just as necessary as a regular supply of fresh water.

So that you do not have to constantly refill the pool, we recommend this chlorine product:

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Exceptional situations, such as an increased amount of combined chlorine, so-called chlorides, which cause an unpleasant odor, or excessive contamination due to algae infestation, can make a change of the pool water unavoidable, but this is the last solution approach, which is rarely necessary.

Once a year, however, it is advisable to change the pool water completely, not only to act hygienically, but also to protect the material, for which the time after wintering is ideal, when the pool is cleaned for the new bathing season.

Save money on refilling the pool

There are a few ways you can use the wastewater removed from your pool and save money one way or another. One purpose for which the old pool water is suitable is to water your own garden, either the flower beds or the lawn, for example, using a sprinkler system.

However, care should be taken to ensure that the water has as balanced a pH as possible, a low chlorine content and no heavy metals, such as those found in many algaecides, so that it does not harm plants.

To regulate the pH, this pH reducer is excellent:

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Other options for disposing of your pool’s water in a cost-effective way that is as environmentally friendly as possible include draining it into the sewer system, using a septic tank, or installing a drywell.

However, you should always pay attention to the chemical limits and inquire about the local legal situation, as it may well vary. In addition, for example, the construction of a dry well, despite its many advantages, is initially very labor-intensive and costly, which must be taken into account during planning.

After draining the pool water of the past year with the individually favored variant, the question arises with which water the pool should be refilled. Well water has the advantage over tap water that it is in principle not so expensive financially, especially for a larger pool.

However, since well water is not of drinking water quality, depending on the region, due to increased contamination with certain germs or heavy metals such as iron oxide, in most cases an addition of additional chemicals or a refill must take place, which can rather be avoided with performance water.

What should be considered after the pool water change?

In order to combine the swimming season with the least amount of chemical, but also physical maintenance of the pool after the pool water change, it is necessary to adjust the water of your pool accordingly.

By checking the water properties, for example, with the help of a test strip or a digital meter, you can get information about the pH value and much other information such as the water hardness, among other things. The former should be between 7.0 and 7.4 for optimal and hygienic use, although deviating values can be adjusted thanks to pH-plus or pH-minus concentrate or granules.

Since both well and tap water may be exposed to various influences before entering your pool, basic disinfection by shocking the pool, is highly recommended, but is no substitute for subsequent regular removal of germs and other foreign matter, such as by chlorine tablets.

Also, worthwhile in most cases is the use of an algaecide, which is used against increased algae growth, and the use of a flocculant, which makes even the smallest dirt particles filterable due to its binding ability.

Against algae in the pool, we recommend this product:

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Important equipment for permanently clear water

Once the refilling of your pool is complete, it is important to prevent the pool water from becoming cloudy in the long term, so that your pool is not only optimally set hygienically, but also positively enriches the ambience of your garden.

Besides, jumping into crystal clear water is more enjoyable than swimming in polluted waters, apart from the fact that it is also much healthier. The following two sections describe the main items needed for this purpose.

Accessories: this section includes all the equipment needed for the physical and manual maintenance of the pool. In addition to a pool net and pool cover, both of which remove or prevent contamination of the water surface by such things as leaves, insects, or pollen, a pool vacuum to clean sunk debris from the walls and bottom of the pool is also a worthwhile investment.

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A sand filter system that removes even the smallest contaminants from the pool water should also not be missing, as well as safety goggles and a pair of chemical gloves, the latter two being used in combination with chemical pool care products.

With this sand filter system, you say war to the dirt in the pool:

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Pool chemicals: to physically clean your pool water and ensure crystal clear swimming fun in your backyard, the use of chemicals to optimize the properties of the pool water is essential. With a pool water test, which is possible either in the form of a digital test device or as a conventional test strip, the composition of the water is checked as well as adjusted if necessary.

With this test device you can achieve excellent accurate measurement results:

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Common pool chemicals include chlorine for disinfection, agents that affect the pH of the pool water, flocculants to supplement the work of the filtration system, and the use of an algaecide to prevent greenish discoloration due to excessive algae infestation.


Unless there are special circumstances, water changes should be performed once a year after the pool has been winterized before it is put back into service and thus before the upcoming swimming season.

Ultimately, however, it is up to each person to decide how often they want to refill their pool. Depending on local conditions, there are numerous ways to dispose of your pool’s old water in a cost-effective manner, taking into account both chemical and legal requirements.

If you want to avoid possible refilling or the additional addition of chemicals in the first place, you should choose the local tap water instead of well water, since in the vast majority of cases it is of drinking water quality.

In contrast to shock chlorination, the use of certain swimming pool chemicals, for example to influence the pH value, should not only be carried out directly after refilling but regularly during the bathing season in order to obtain visually and hygienically perfect swimming pool water.

To ensure that you can always enjoy crystal clear water and intact pool materials during the summer months, it is advisable to combine chemical water care with physical cleaning measures. Taking into account the above-mentioned aspects, the pool filling, in addition to visually enriching your garden, will be most noticeable in the form of a refreshing bathing experience.

Recommended read: How to Properly Empty a Pool (+ how to use Drain Water)

Larry has been a true water rat since childhood. Pure pleasure turned into a passion. That's why he is the first point of contact for friends and acquaintances when it comes to pool-related problems. He is an integral part of the PoolHandbook editorial team.