Pool Care Pool Maintenance

5 Ways to Get Rid of Calcium Scales in Pool

pool waterfall with calcium scales

If you’ve started noticing a hard, off-white chalky substance forming around the water line that is becoming almost impossible to clean the regular way, you’re dealing with calcium scaling. It starts like white foam and turns to a thick, chalky substance that you can’t seem to clean with regular brushing. So, how do you remove the calcium scale from the pool?

You have a couple of options, with the easiest and the most convenient being to use muriatic acid or white vinegar spray with before- and after-scrubbing. You need to add the right amount of the solution to prevent causing havoc to the pool chemistry. The before-scrubbing exposes the scale to the acid while the after-scrubbing dislodges it from the surface.

As you can tell, removing calcium scale from your pool is relatively easy. All you need is a properly laid out process, and the scaling will be at the mercy of your hands, something covered quite well in this post. Continue reading to know more about what it is, how to remove and prevent it from coming back.

What is the Best Way to Remove Calcium Scale from Pool

If you can’t seem to get rid of the off-white chalky and scale stuff around your pool’s waterline, you might want to try out something else other than your typical cleaning technique.

The typical pool brushing can’t even shake it. But don’t worry, the following tricks will help you get away with it. What you will need is some patience. Let’s get to it.

1. Use of Muriatic Acid

Muriatic acid or dry acid is the easiest and best way to remove calcium scale from a pool. The acidic nature of muriatic acid reacts with the calcium compound formed. All you need is to spay some of the solutions to the scaled surface, soak the substance and brush it off with a stiff brush.

However, since you’ll be dealing with acid, it’d be best to take some safety precautions. Wear the proper protective gear, including a mask, goggles, gloves, and clothes covering your skin from accidental spill to the skin.

2. Use of Vinegar

If the scaling isn’t too bad – only some light scaling, you might be able to remove it by using a vinegar-water solution in a spray bottle.

Scrubbing will also be necessary. It’s the most appropriate method for some surfaces, such as especially on ceramic tile and vinyl.

3. Pumice Stone

If you’re not a fan of acid and vinegar isn’t helping, you can try giving it a little grit and burn some elbow grease by using a pumice stone to scrub the calcium scale off your pool surfaces.

The technique can only be used on a ceramic and concrete surface. The stone can scratch or damage those soft surfaces such as glass tiles, fiberglass walls, and vinyl liners.

You will also need to drain your swimming pool a few inches below the scaled line. The pumice stone and the wall surfaces have to stay wet.

Start scrubbing the surfaces slowly and in a circular motion until you remove all the scaling.

4. Stain Eraser Brush

If you’re trying to get rid of tiny calcium buildup, you could use a stain eraser brush, a type of pool brush designed for gentle brushing of a variety of pool finishes.

However, it might require you to add a calcium remover agent to soak the scaling substance and then use the brush to remove it.

5. Calcium Scale Removing Agents

You can also use chemicals formulated to remove the scaling from the pool surfaces. You can get them in a pool store near you or an online store.

Most of them are in solution form. You’re required to spray and soak the calcium compound deposits and then gently brush them off.

It’s best to make sure the product is compatible with your pool sanitizer and safe for use on your pool surfaces. Get all this information by checking the product description before purchase.

How Do You Remove Calcium Scale from Specific Pool Surfaces


Swimming pools are made differently. Their finishes vary, and so do the methods of removing the calcium scale. Here are ways you can remove the scaling from various standard pool finishes.

1) Plaster Surfaces

Calcium scaling on plaster surfaces tends to be quite stubborn. You could use a stain eraser brush, but you will need a removal agent if the scale is more settled, the best being muriatic acid. Soaking the deposits will make it easier for you to brush them out of the surfaces. Regular pool wall brushing can also help clean up the buildup.

2) Tile Surfaces

Tiles are a bit tricky to clean calcium scale off. That’s because delicate to work with. You can try scraping the deposits with a putty knife or anything of a similar design. However, you might want to be diligent as you can potentially damage the tiles and end up with expensive repairs on your plate.

You can also avoid this and decide to use a stain remover brush such as a stainless steel wire brush or sandpaper wrapped on a typical pool brush. Again, if the scaling isn’t going away with the scrubbing, try applying the chemical agent to loosen it.

3) Vinyl Liner

The calcium scale tends to leave lasting stains on some surfaces, such as vinyl liners. Even though the material is one of the easiest to clean, they are also quite delicate. It’d be best to handle it with care. You need a soft brush or even use a sponge. If it’s hard to get rid of by brushing, use the vinegar-water solution as a calcium scale removing agent.

What is Calcium Scale Anyway?

The calcium scale, at times, is known as limescale. It’s often defined as a chalky substance mostly found on surfaces of water-operated machinery. That is the same stuff that you might see developing around the swimming pool waterline. The scaling starts like white foam before the foamy looking white stuff turns into a hard, rocky substance that sometimes becomes impossible to remove. So, in short, the calcium scale is simply that.

What are the Types of Calcium Scale in a Pool

The calcium scale comes in two types. Mainly determined how it’s formed. The two common types are:

1. Calcium Carbonate

Calcium carbonate is mainly known as a dietary supplement known for rigid bones and keeping the body healthy. Though, it’s the same whitish mineral that forms in your pool. However, it’s it does not have the same charm.

It’s the most commonly white and flakey calcium scaling in swimming pools, typically occurring after the water evaporates. It’s pretty easy to remove, and it doesn’t stain the pool surfaces.

2. Calcium Silicate

Now the thing you don’t want to deal with is a white-grey substance, calcium silicate. It’s not easy to get rid of, and most of the time, pool owners seek professional help.

The calcium silicate scaling becomes an issue for your pool, its plumbing and the filtration system. You can still do away with it, but it might test your patience and grow you some muscle. You could use muriatic acid for the removal of the calcium silicate.

So, how do you differentiate between the two?

The same muriatic acid is the same chemical you can use to differentiate the two. Apply some drops of dry acid directly on the whitish surface. If you see any fizzling and bubbling, it’s the good calcium carbonate scale. If you don’t observe any reaction, then, oh my, it’s calcium silicate.

What Causes Calcium Scale in a Pool?

Majorly, calcium occurs when you use hard water in your swimming pool. The increase in the calcium mineral in the swimming pool can increase the calcium ions, normally 400ppm. It’s the same thing you might have seen on the showers, tubs, or sink drains. It’s a problem faced by most people that live in an area that has hard water.

It’s the same result you get when you use a lot of calcium hypochlorite shock. This pool shock adds calcium when the chlorine is all used up. However, the amount isn’t enough to cause the scaling, but when combined with the hard water calcium, that is enough to cause the calcium scale.

Another cause of the calcium scale is unbalanced water chemistry. When the alkalinity and pH levels are high, it creates a perfect environment for scaling. However, it’s the high water temperatures that seal the deal. It makes the perfect recipe for the calcium scale to occur.

Why Is Calcium Scale A Problem?

Apart from creating all the aesthetic menace, calcium buildup scaling can cause damage in the long run. The scaling can cause corrosion to the pool surfaces, mainly fiberglass and vinyl liner causing pretty nasty stains.

Besides this, the scaling buildup might not just happen on the pool surfaces; it can extend to other parts of your pool. It’s capable of clogging your filter, coat the pipes, or wreak havoc on all the operational features of your swimming pool. It might even erode materials in pool tiles, ladders, fiberglass, grout, and liner.

How Can You Preventing Calcium Scaling

Calcium scaling can take a lot from you trying to remove it. So, the best thing you can do is to prevent it from ever happen. You can take the following precautions:

  • The best place to start is by ensuring your pool chemistry stays balanced. The pH has to be between 7.2 to 7.4 and alkalinity between 80 to 90ppm.
  • A pool clarifier can also help clump the calcium films together, and you can vacuum them later, or your pool filter will help clean them.
  • Brush the pool surfaces regularly to get rid of the few calcium building up before things get worse.
  • Practice vacuuming when you brush your pool to pick up any calcium that might have build up.
  • Also, avoid using hard water. If there is no other option, get a hose filter to clean up the minerals, including calcium ions.
  • If you seem to be battling unusually high amounts, avoid shock with added calcium like calcium hypochlorite
  • Brush your pool regularly to keep calcium from building up
  • Vacuum your pool every time you brush it to pick up loose calcium

Related Questions

What is the proper calcium level for a pool?

The ideal Calcium hardness levels in a pool should be around 150 – 400ppm (part per million). You can use a pool testing kit to check if your pool’s calcium hardness is balanced correctly.

About the author

Sharif Miah

Hi! I'm Sharif, the founder of Globo Pool® and I have been working in the pool & hot tub industry for the last few years. I love to share my experiences with people & hope you are enjoying my information and lessons!

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