Acid Pool Wash: How To Remove Lime Deposits From Your Pool?

When pool maintenance gets overlooked, and pH levels rise beyond 7.6, the unsightly phenomenon of lime deposits often rears its head. Although limescale poses no direct harm to human health, its presence can compromise pool equipment and affect the clarity of the pool water. Predominantly, the presence of lime can be attributed to poor grouting or age-related limescale damage. Solving this issue involves a comprehensive acid wash, using hydrochloric acid, which can be implemented in both filled and empty pools.

The process of lime removal from a filled pool can be summarized in eight key steps.

  1. Turn off the pump.
  2. Pour the acid.
  3. Wipe off splashes.
  4. Allow acid to sit and check pH.
  5. Let pool rest.
  6. Brush and vacuum pool.
  7. Check pH level.
  8. Repeat if necessary.

For an empty pool, the process is somewhat simpler, comprising of five steps.

  1. Drain pool and close floor drain.
  2. Prepare acidic solution.
  3. Apply solution.
  4. Scrub pool.
  5. Dispose of acid solution.

To prevent future lime deposits, regular water care is paramount. Keeping a consistent pH level of 7.2 to 7.6 and a water hardness of 200 to 400 ppm is the first line of defense against limescale. This preventive approach is likely to save pool owners significant time and effort in the long run. However, if the pool water still turns milky despite optimal treatment, other causes beyond lime deposits should be investigated.

Moving forward, let’s delve deeper into these methods and explore the nuances of lime removal from your pool.

What Causes Lime In Your Pool?

Lime tends to make an unwelcome appearance in your pool when the pH level exceeds 7.6 and the pool maintenance is overlooked.

It’s not uncommon to find age-related limescale damage or deposits due to poor grouting.

While limescale is harmless to us, it can wreak havoc on your pool equipment and turn your pool water milky.

Regardless of the type of limescale problem in your pool, it’s essential to remove the lime.

The solution to your lime problem lies in a complex acid wash. This cleaning process with hydrochloric acid can be performed in both a filled pool and an empty basin.

After understanding both methods, you can choose the one that suits you best.

How To Clean Lime Deposits In A Filled Pool?

Here is an eight-step troubleshooting guide on how you can remove limescale from your pool without having to drain the water.

  1. Turn off the pool pump to prevent splashes.
  2. Pour approximately 10 liters of hydrochloric acid into various points in your pool for every 25 m³ of pool water. Remember to wear a respirator and protective goggles.
  3. Wipe off any splashes on the pool edge to avoid acid stains on your pool surface.
  4. Let the acid sit for about 30 minutes and then measure the pH. If it’s not well below 7.0, add more acid.
  5. Let the pool rest for a day, allowing the acid to do its job.
  6. The next day, brush the pool using a pool brush, starting with the walls and then the floor.
  7. After an hour, vacuum the pool.
  8. On the third day, start the pool pump and brush the pool again. If limescale deposits are still visible, continue scrubbing until all lime deposits are removed. Ensure the pH level is below 7.0.

You are wondering where do you get hydrochloric acid? Just use a pH minus agent because that’s nothing more than hydrochloric acid.

Once the limescale has been removed from your pool, the pH level must be brought back to an average level of 7.2 to 7.6. This can be easily achieved with a pH plus.

But you also have to check all other parameters such as total alkalinity and water hardness in your pool – improve them if necessary. Ideally, you should do the acid wash of your swimming pool after the main season because removing the calcium can take several days. If your pool has not yet been filled, you can do the acid wash before filling it for the first time.

How To Remove Lime From An Empty Pool?

If your pool is empty, here are five tips how you can remove limescale.

  1. The pool must be drained, and the floor drain must be closed with a stop.
  2. Put on a respirator, goggles, and rubber gloves to protect yourself from splash and fumes.
  3. In the bucket, an acidic solution is dissolved with water in a mixing ratio of 2:1 (2 parts water and 1 part acid).
  4. The mixture is scrubbed quickly with a scrubber on the affected areas – start with the pool walls.
  5. After washing, the acid solution that has accumulated on the floor drain must be disposed of – follow the legal regulations of your place of residence.

Before you wash the empty pool with acid, ask your local environment agency how the contaminated wastewater – after lime cleaning – has to be disposed of.

You should wear old clothes when washing with acids, as acid splashes could damage your clothes. If you don’t have additional goggles, at least wear sunglasses.

To get rid of the lime in your pool is extremely time-consuming, and it is easier to prevent these types of deposits. This works best with proper water care in your swimming pool.

How To Clean Limescale From Pool Walls?

For minor limescale, a sponge and a bit of hydrochloric acid can do the trick. Follow these three steps.

  1. Apply some of the hydrochloric acids to a pool sponge.
  2. Wipe the limescale with an outstretched arm until the lime has been removed.
  3. After using the acid, check the pH level in your pool and improve it if necessary.

If the limescale is severe, let the acid act for about 30 minutes before brushing it off.

Beware of the rising gases when using – this is not very pleasant. Therefore, you should never hold your face over the sponge. Remove the limescale with your arms outstretched.

How To Prevent Lime Deposits In Your Pool?

Preventing limescale build-up is easier than removing it. Proper water care is key.

If you maintain a pH level of 7.2 – 7.6 and a water hardness of 200 – 400 ppm, limescale shouldn’t be a problem in your pool.

Here are four tips from pool experts to keep lime at bay.

  1. Regularly Check the pH Level: The pH level of your pool water plays a crucial role in preventing lime build-up. Regularly check the pH level and ensure it stays between 7.2 and 7.6. A pH level of 7.4 is considered ideal.
  2. Monitor the Calcium Hardness: Lime hardness, also known as calcium hardness, should be measured once a month. Aim to keep the level at 300 ppm for optimal results.
  3. Use a Flocculant: A pool flocculant can help bind the fine limescale deposits, making it easier for your sand filter system to filter them out.
  4. Invest in an Electronic Water Tester: This device can quickly and accurately check all parameters in your pool, including pH level and calcium hardness.

With an electronic water tester, you can quickly check all parameters in your pool and, above all, determine them much more precisely than with simple test strips.

But what if your pool water turns milky despite optimal treatment?

If you’ve followed all the tips mentioned here and your pool water still turns milky, then lime isn’t the problem. In such a case, it’s crucial to investigate other potential causes. I’ll delve into the causes of milky pool water in a future article.

Do you have any further questions about calcium and limescale in your pool and how to remove it? Contact me on Twitter, Facebook, or YouTube. I am happy to help you personally.

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Conan Grout is a renowned pool care expert, specializing in maintaining optimal water chemistry, crucial for a healthy swimming environment. His expertise covers essential practices like regular pH, salt, and chlorine level checks, debris skimming, and algae-preventing brushing. Additionally, Grout is adept in advanced pool cleaning techniques, including the use of nonabrasive chlorine-based solutions for challenging tile scum. His comprehensive skill set makes him a trusted authority in swimming pool maintenance.