If the water hardness exceeds 400 ppm, you can expect limescale in your swimming pool. The limescale deposits lead to fogging pool walls and filter sand. In the worst case, a persistent limescale forms, which is difficult to clean and turns the pool water milky. What to do and how to remove the limescale?
The best way to remove calcium scale in the pool is with hydrochloric acid. The acid is applied to a sponge, and then the lime is wiped off. If there is strong limescale, the acid must act for 30 minutes and later be removed with a brush.
In this article, you will learn the most common methods of how to remove calcium scale in a drained or filled pool. I will also give you practical tips to prevent limescale build-up.
What should you do if there is calcium in your pool?
Lime in the pool always occurs when the pH level is above the limit of 7.6 and the maintenance of the pool is neglected.
Age-related limescale damage or deposits because of poor grouting in your pool are also not uncommon.
The limescale is harmless to humans, but the consequences of limescale deposits in your pool are damaged equipment and milky pool water.
It doesn’t matter what kind of limescale problem occurs in your pool, the calcium must be removed.
The only question is: How do you remove the calcium out of your pool?
A complex acid wash is necessary to remove the lime.
The cleaning with the hydrochloric acid can be done in a filled pool an empty basin.
You can decide which washing you prefer yourself after learning both methods.
Pool calcium removal in the filled pool
In this guide, I will explain how to remove limescale from your pool without emptying the water.
- First, switch the pool pump off to avoid splashes.
- Then pour around 10 liters of hydrochloric acid into your pool at various points for every 25 m³ of pool water – it is essential to wear a respirator and protective goggles.
- Check the edge of your pool and wipe any splash off the crown to prevent acid stains.
- Let the acid sit for about 30 minutes and measure the pH. The pH level should be well below 7.0. If this is not the case, more acid must be added to the pool water.
- The pool must rest a day long. The acid will work now in your favor.
- The next day, the pool is brushed using a pool brush. Start with the walls and then scrub the pool floor.
- Let the pool rest for about 1 hour, and then vacuum the pool with a pool vacuum.
- The next day the pool pump is started, and the pool is brushed again – it is normal for clouds to form in your pool.
- If you still see limescale deposits on the third day, the swimming pool must be scrubbed again until all calcium deposits have been removed. The pH level must be below 7.0 (top up with acid if necessary).
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.
Tip: 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.
Pool calcium removal in the empty pool
In this guide, I will explain how to remove the limescale in your pool after emptying the pool.
- The pool must be drained, and the floor drain must be closed with a stop.
- Put on a respirator, goggles, and rubber gloves to protect yourself from splash and fumes.
- In the bucket, an acidic solution is dissolved with water in a mixing ratio of 2:1 (2 parts water and 1 part acid).
- The mixture is scrubbed quickly with a scrubber on the affected areas – start with the pool walls.
- 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.
Tip: 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.
Cleaning limescale from the pool walls
Slight limescale in your pool can be removed with a sponge and a little hydrochloric acid.
- Apply some of the hydrochloric acids to a pool sponge.
- Wipe the limescale with an outstretched arm until the lime has been removed.
- After using the acid, check the pH level in your pool and improve it if necessary.
If the limescale is very pronounced, the acid must act for about 30 minutes. Then the lime is removed with a brush.
Tip: 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.
Conclusion on the acid washing of the pool
The instructions explained are the most common methods of removing limescale deposits in a pool.
But which of these methods is best?
I prefer acid washing in a filled pool. The reason for this is that this method is much more environmentally friendly than acid washing in an empty basin.
On average, it takes a little longer to clean the limescale in a filled swimming pool, but in the end, you don’t have to remove the acid-contaminated water.
Limescale cleaning in an empty standing pool is only suitable if serious damage has occurred to your pool.
In the end, it is up to you to decide which procedure to remove the calcium from your pool.
One question remains to be answered: Can you remove the limescale in the pool with a home remedy?
Home remedies to get rid of pool limescale deposits are in demand but not always the best way to remove stubborn limescale build-up.
An acidic household remedy such as citric acid or vinegar is okay when you have a slight limescale problem. But if the limescale edge is worse, special pool cleaners are the better choice.
It takes several days to remove the limescale with a strong hydrochloric acid in your pool. With simple home remedies, pool cleaning would take forever.
Tips against calcium in the pool water
Limescale cleaning in your pool is time-consuming, and I recommend that every pool owner keep the water balance upright so that there are no problems with calcium.
You have to know that the water hardness and the pH level in your pool maintenance play a big part.
If you keep the pH level at 7.2 – 7.6 and the water hardness (also known as calcium hardness) at 200 – 400 ppm, then there should be no limescale in your pool.
In forums, you often read the tip that you should keep your pool cool to avoid limescale build-up.
This is true but not a realistic solution.
The water temperature would have to be well above 149 °F so that there would be a heavy build-up of limescale.
Who would heat the pool water above 149 °F?
Just remember the following tips from pool experts, and calcium in your pool will no be longer a problem:
- Check calcium hardness: Measure the calcium hardness/water hardness once a month and ideally keep the level at 300 ppm.
- Lower the pH level: Check the pH level in the pool water every day with test strips and keep the value between 7.2 and 7.6 – A pH level of 7.4 is ideal.
- Use flocculant: The pool flocculant can help bind the fine limescale deposits and filter them out with the sand filter system.
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 you get milky pool water despite optimal treatment?
Is the lime the cause, and what should be done in this case?
If you’ve followed all of the tips mentioned here and your pool has turned milky, then limescale isn’t the problem.
In the following article, I’ll go into the causes of milky pool water – click on the link to read the blog article.
Do you have any further questions about calcium and limescale in your pool and how to remove it?
Contact me at @contactswimfool on Twitter, Facebook, or YouTube. I am happy to help you personally.
In this sense. Good luck lowering the calcium in your pool.