Pool ORP (How to Raise The ORP Level in Your Pool)

The pool orp can be used to measure the quality of your water in the pool. But how exactly is the orp level in a pool measured and optimized?

The pool orp indicates how high the germicidal effect of the disinfectants used in a pool is. The optimum of the orp level in a swimming pool is between > 700 – 750 mV to achieve a germicidal speed of 104 within 30 seconds, according to DIN 19643.

In this article, I will explain everything about the pool orp (redox voltage) and why the orp testing in private swimming pools can be neglected.

What does the pool ORP Level mean?

In addition to the TDS level, the pool ORP (redox voltage) is also measured to determine the hygienic condition of the disease and the associated water quality.

But what exactly does the pool ORP mean in your pool water?

With the help of the pool ORP level, the germicidal effect of the disinfectants used (like chlorine, bromine, active oxygen, or biguanides) in the pool water is determined.

The measured ORP level ​​provides information about the organic dirt particles and how oxidative the pool chemistry works against the contamination.

DIN 19643 requires a germicidal speed of 104 within 30 seconds. Source.

So there is a direct correlation between the free chlorine and the ORP level in your pool water.

Tip: You can read more about the TDS level in your pool in my blog. To do this, click on the link to access the article.

How is the pool ORP level tested?

The pool ORP is usually tested continuously using an automatic machine to assess the hygiene conditions in the pool water.

If you want to do this in your private pool, you can do it with the following device.

The proportion of free chlorine, the pH level, and the amount of colloidal substances in the water are considered during the measurement.

Manual devices are now also available to measure the redox voltage in your swimming pool.

To do this, however, the pH level in your swimming pool must first be tested and, if necessary, optimized to get the most precise measurement result possible.

Rule of thumb: With a pH level of 7.4, the pool ORP should be 750 mV.

At this point, it must be mentioned that the pool ORP is tested only relatively rarely in private swimming pools and that it makes more sense to use it in public swimming pools.

How high should the pool ORP level be?

Pool water with an ORP level above +750 mV is considered sufficient, but the measured level of the redox voltage varies depending on the type of pool.

As mentioned above, the redox voltage is always measured considering the pH level and the free chlorine in your pool – a generalized statement is difficult.

The following table shows how high the pool ORP level should be in your pool water.

Pool Free Chlorine pH Level ORP Level
Freshwater 0,3 – 0,6 ppm 6,5 – 7,6 750 bis 770 mV
Salt water 0,3 – 0,6 ppm 6,5 – 7,8 700 – 720 mV

In order to guarantee the germicidal rate – taking into account the redox voltage – a chlorine level of 0.3 ppm is prescribed in your pool.

The table refers to a measurement in a pool, but the same values ​​apply to hot tubs according to DIN 19643.

If the redox level is too high, this can indicate too much chlorine in your pool. You can learn how to reduce the chlorine level in my blog.

Tip: If the pool ORP level is to be coordinated with the pH level in your pool, then test strips should not be used because of the risk of measurement errors. In this case, the pH level should be determined with an electronic water tester.

Read more about pool water testing in my blog post. Click on the Link to open the article.

How can you increase the ORP level in your swimming pool?

If the ORP level in your pool drops, this does not have to mean that there is not enough free chlorine in your pool water.

A decrease in redox voltage while maintaining the free chlorine content indicates poor pool maintenance or suggests that your pool water is overloaded.

In that case, I can recommend my article on using pool chemistry.

You can also increase the pool ORP level by applying a pool flocculant to reduce the concentration of all pollutants in your pool water – you will find a helpful explanation on this in my blog.

Do you have any further questions about the pool ORP level?

Contact me at @contactswimfool on Twitter, Facebook, YouTube, or Pinterest – I’ll be happy to help you personally.

I hope this post was helpful, and you enjoy swimming in your pool.

Photo of author
Hi. I'm Max Berg. I've been in the pool industry since 2015 and have always felt drawn to water. I'm the author behind swimfool.com, where I share my years of experience in pool maintenance and give helpful tips on keeping a swimming pool or hot tub clean. My tips reduce the costs of water treatment and protect the environment.

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