5 Easy Tips to Understand Calcium Scaling in Pool
Keeping your pool clean can take a lot of work, but as a responsible pool owner, you're doing all the right things—balancing the water, brushing, and vacuuming. Usually, your pool stays sparkling clean. However, you might start to notice something unpleasant: white scale building up on the sides of your pool. You may see white bumps on the walls, railings, and ladders, or even experience the annoying "pool toe." This is caused by calcium scaling in the pool, which leads to calcium deposits in the pool. It’s a sign that calcium is building up on your pool surfaces, and it won’t just disappear on its own. If you're dealing with calcium scaling, you know it can be tough to get rid of. But don’t worry—it’s something you can tackle!
1. Types of Calcium Scaling in a Swimming Pool
There are two types of calcium scaling in pools, and one is much harder to deal with than the other. The most common type is calcium carbonate. While it can be a hassle, it’s something you can remove with some effort. The tougher type is calcium silicate. It forms more slowly, but once it’s there, it’s very hard to get rid of on your own. What’s worse is that if you have calcium silicate scaling in your pool, you likely also have buildup in your pipes. This type of scaling requires professional help to remove. You can tell the difference between calcium carbonate and calcium silicate by adding a drop of muriatic acid to the scaling. If it reacts and foams, it’s calcium carbonate. If nothing happens, you have calcium silicate.
2. What Causes Calcium Scaling
Since calcium silicate is tough to handle, let’s focus on calcium carbonate scaling in pools. Calcium scaling from calcium carbonate happens because of a few factors working together. First, you need high calcium levels in the water, usually above 400 ppm. This often comes from hard water. If you live in an area with hard water, you’ve probably seen calcium deposits on drains in sinks, showers, and tubs. Many homeowners in such areas use water softeners, but the water filling your pool likely doesn’t come from your home taps. If you don’t live in an area with hard water, high calcium levels might be from using calcium hypochlorite shock. This type of shock adds calcium to the water, potentially leading to high calcium levels. But simply having high calcium levels doesn’t automatically cause scaling. The second factor is water chemistry. High alkalinity and pH levels create the ideal environment for calcium scaling to occur. The final factor is high water temperatures. When you combine high alkalinity, high pH, and high water temperatures with hard water, it’s the perfect storm for calcium scaling in your pool.
3. Removing Calcium Scaling
If you have calcium scaling in your pool, there are a few ways to get rid of it.
Start with low-impact methods, like adding stain remover to your pool water, which most pool stores carry. Just make sure it’s safe for your pool material, especially vinyl, which can be damaged by some cleaners.
For small areas, you can scrub away the scaling using a mild acid like vinegar. Simply pour or spray it on the scaling, then scrub with a toothbrush, pumice stone, or fine sandpaper. This is effective for hard surfaces, but avoid abrasives on vinyl liners to prevent tears.
If the stain remover alone doesn’t work, use a nylon brush for vinyl pools.

4. Using Muriatic Acid to Remove Calcium Scaling
If vinegar and pumice stone aren’t working, muriatic acid is a more powerful option—but it’s strong and requires safety precautions.
Here’s how to use it:
Materials you’ll need:
- Muriatic acid
- Plastic bucket
- Plastic measuring cup
- Plastic spoon
- Plastic spray bottle
- Scouring pad
- Safety goggles, rubber gloves, and respirator
Steps:
- Put on your safety gear (goggles, gloves, respirator).
- Take everything outside (never mix the solution indoors).
- Fill the bucket with one gallon of water.
- Slowly add 8 oz. of muriatic acid to the water—always add the acid to the water, not the other way around, to avoid splashing.
- Stir the mixture gently with a plastic spoon.
- Pour the solution into the spray bottle.
- Spray the solution onto the calcium scaling. It will foam and react.
- Let it sit for a minute, then scrub the area with a non-abrasive scouring pad (avoid damage to pool walls).
Make sure you do all of this from outside the pool and avoid reentering until the pH is properly balanced. Don’t reenter the pool until you have adjusted the pH back to a safe level.
5. Going the Professional Route
There are plenty of good reasons to hire a professional for calcium scaling removal. If you’re using the vinegar and scrub method, it can take hours of hard work, depending on the size of the area. If you’d rather avoid that physical effort, professionals can handle it for you. The Pool Butler doesn’t use the vinegar and scrub method. We use professional-grade solutions to quickly and efficiently remove the scaling. If you’re considering muriatic acid, this is even more of a reason to go with the pros. Muriatic acid is dangerous if mishandled and can cause your pool’s pH to drop significantly. If you don’t want to deal with a strong acid or rebalance your pool’s chemicals, leave it to the experts. The Pool Butler has the tools and expertise to get the job done quickly and safely. If you’re dealing with moderate to severe calcium scaling, contact us for a free consultation. We’ll assess the best solution and provide the professional care your pool needs.
Let The Pool Butler Handle Your Calcium Scaling!
Dealing with calcium scaling in your pool can be tough, but it’s crucial to address it quickly to prevent further damage and keep your pool looking great. Identifying the type of calcium scaling and understanding its causes will help you choose the right method for removal. For mild scaling, stain removers and mild acids like vinegar can work with a bit of effort. But when the scaling is severe, extreme caution is required. Muriatic acid can be effective, but it’s a hazardous solution best left to professionals to ensure safety and proper handling.
For safe, efficient, and professional scaling removal, trust The Pool Butler. We have the experience and tools to get the job done right—quickly and without the hassle. Don’t risk damage to your pool or your safety. Contact us today for a free consultation and let us restore your pool to its sparkling best!
