For many people, a pool is one of the amenities of their own garden. For lasting joy, everything has to fit on the technical side. This is what you can do if the pH in the water is too low.

In a nutshell

  • Incorrect water characteristics have a detrimental effect on technology, the environment and people
  • special pH raisers and other pH-raising chemicals are equally suitable
  • Chemicals can be saved preventively if the acidification of the pool water is prevented

What do low pH values mean?

The pH value indicates how acidic or basic the water quality is. A pH value that is too low means that the water is too “acidic”. This has several negative effects:

  • Increased corrosion of the components
  • Health impairments for bathers, especially the skin as a protective barrier
  • Decreased effectiveness of other pool chemicals, especially chlorine

The optimal range

A value between 7.0 and 7.4 on the well-known pH value scale from 0 (very acidic) to 15 (very alkaline) is optimal for pool water. If it is too low, you should take appropriate measures to increase it to protect yourself and your pool.

Notice: Depending on the pool size and design, the optimal pH value can vary slightly. Make sure you get clear information from your pool system manufacturer about the ideal water level to aim for.

Determine the pH value

Be sure to determine the actual, daily updated pH value of your pool based on the pool volume. Because the value can continue to change within a short time due to these influences:

  • temperature fluctuations
  • changes in tanning
  • Use of other pool chemicals
  • Entry of other foreign substances, such as dirt
  • bathing operation

A determination immediately before raising the pH value is therefore essential for the correct dosage and the desired effect. Test strips are a common means of determining the pH value. These are wetted with pool water and change color depending on the water quality. An enclosed color scale then enables the existing pH value to be read off immediately.

The pool volume

No matter which measures you want to use to increase your pH value, you will always need the amount of water in the pool as a basis for the calculation. Therefore, if you do not already know the amount, first determine the pool volume:

Rectangular pools:

  • Length x width x water depth, each in meters (m) = volume in cubic meters (m3)
  • Example: width 5 meters, length 8 meters, depth 1.50 m
  • 5.00m x 8.00m x 1.50m = 60.00 m3 water volume

Round pools:

  • Base area according to the circular formula Pi x radius² x water depth, each in meters (m) = volume in cubic meters (m3)
  • Example: diameter 5.00 meters, depth 1.50m
  • 3.14 x (2.50m)² x 1.50m = 29.44 m3 of water volume

Tip: If your pool is not circular or rectangular, break down the base area into easily identifiable sub-areas as best as possible. For example, an oval pool can easily be broken down into an almost congruent rectangle and two semicircles at the ends. You can then calculate this using the formulas above.

pH raiser

The easiest way to increase the value is to use ready-made preparations from relevant pool chemical suppliers. These so-called pH raisers are sold either as granules or in liquid form as a solution. Depending on the dosage of the preparation, a certain amount is required per cubic meter of pool water. It is therefore essential to study the manufacturer's information on dosage in order to increase the water quality by the required value.

soda

Many “professional” pH raisers contain soda, i.e. sodium carbonate. Instead of the often expensive pool chemicals, you can also use the much cheaper washing soda as a home remedy. About 5 grams of soda per cubic meter of pool water raise the value by 0.2.

example
Starting position:

  • Existing pH 6.6
  • Target value 7.2
  • Pool volume 60 cubic meters

Action:

  • Determination of the value to be increased: 7.2 - 6.6 = 0.6
  • Determining the amount of soda per cubic meter of water: (0.6 / 0.2) x 5 grams of soda = 3 x 5 grams = 15 grams of soda
  • Determining the absolute amount of soda: Pool volume x amount of soda per cubic meter, i.e. 60 m3 x 15 grams = 900 grams of soda

Attention: When using washing soda, the amount and effect is less accurate than when using specialty pool chemistry. Therefore, slowly approach the desired result and measure again after each dose of soda and after a reasonable waiting time.

How to use chemistry?

For optimal success, you not only need to know the right means, but also how to use them. Generally speaking, the use of special pH raisers, as well as soda in its pure form, is very simple. However, there are a few things to consider:

The conditions

So that your efforts are not in vain, the pool water should correspond as far as possible to the later bathing conditions when using the agents. In this way you avoid that changes in the framework conditions require repeated reworking. In particular, these factors should already be in the area of later use:

  • amount of water
  • water temperature
  • Added pool chemicals such as chlorine or active oxygen
  • Completed cleaning (due to acidic or alkaline cleaning agents)

The addition

Now comes the actual work step, when you put the determined and measured amount of the selected chemical into the pool:

  • Always put substances in the free pool water to avoid damage caused by short-term extreme dosages in the skimmer, pump, etc
  • Switch on the pump with filter and leave it in operation until the chemicals have completely dissolved
  • Keep the system running for about 10 more minutes for even distribution in the water
  • Measure the result obtained using a pH test strip
  • If necessary, top up in the same way

Prevent pH changes - save chemicals

Chemicals cost money and ultimately always mean the risk of incorrect dosing and accidents during handling. So what could be more obvious than to limit the use of pH raisers to the absolutely necessary minimum? There are various starting points to prevent possible reductions in the value:

  • Cover the pool when not in use to prevent the pool water from acidifying due to acid rain
  • Cleaning ideally with pH-neutral cleaning agents
  • Reduce other pool chemistry to the minimum necessary as they usually interact or influence water characteristics

frequently asked Questions

Despite the correct dosage, I do not reach the desired pH range. Where is the mistake?

Unfortunately, there is no universal error source for deviating results. Either deficiencies in the chemicals used or other influencing factors on the water quality come into question. Check all the points already mentioned step by step in order to track down the error.

Does washing soda have disadvantages compared to "real" pool chemicals?

From a chemical point of view, pure washing soda is identical to the sodium carbonate used in special pool chemicals. Additives to increase the washing performance that adversely affect the pool water could be problematic. So make sure they actually use pure sodium carbonate.

What do I do if I overshoot the target?

Once you have raised the pH value above the target value, you will hardly be able to avoid taking countermeasures with pH reducers. Because pool water that is too alkaline also has adverse effects on the pool chemistry, the technology and, last but not least, the bathers.

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