How To Remove Calcium Scale Deposits From Your Pool Wall

Written by:  Danny Rhodehamel

Scale deposits can form along the waterline of your swimming pool. This is usually caused by either high pH, high alkalinity, or a high calcium concentration. Constant temperature changes along with rapid evaporation will cause deposits to settle along the side your pool wall. If the deposits are not removed soon, it can cause permanent damage to the pool surface.

Tips & Warnings

Step by Step

Step 1

The first step it to stop all swimming pool use until a water test can be performed. If the test reveals that the levels are within range, you can use a stain and scale remover to remove the deposits from the water line. If the pH, alkalinity or calcium levels are too high, they will need to be lowered before using a stain and scale cleaner.

Step 2

I recommend starting by lowering the calcium hardness first. Calcium can only be lowered by partially draining and refilling the pool. Your swimming pool needs a calcium level of 200-400 ppm. A calcium level higher than 400 can lead to scale of the pool surface and equipment and can also cause cloudy water.

Step 3

Once the pool has been drained, re-filled and the calcium is back within range, you can adjust the alkalinity. You will want to re-test before doing so because the alkalinity should be lower than before. To lower alkalinity, you can use either dry acid or muriatic acid. The amount needed of either chemical will vary depending on the pool size (gallons) and the alkalinity reading. If the alkalinity needs to be increased, you can follow the instructions on:

How To Maintain A Swimming Pool Part 3 (Adjusting Chemicals)

Step 4

Once the alkalinity is within range, the pH can be adjusted (if necessary, you can use the same guide as in step 3). Once the pH is balanced, we can move onto the final step.

Step 5

The final will be to use a surface cleaner to remove the build up. Before adding the product, (following the instructions on the container) make certain to have a pool brush handy to brush down the walls as needed.

Step 6

Your pool walls should be looking alot better at this point and you can resume swimming.

Comments (1 to 11 of 11)

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User: Inyopools

Robbie - For the scum marks on the upper wall and grout, many people and used half a 3" chlorine tablet to scrub over the affected surfaces. Use gloves. The scale on the bottom of the pool will have to be brushed off with a stiff brush.

User: Robbie

Hi I have just purchased a house with a indoor pool. The pool has been empty for about a year and a half and is of concrete construction with a tile bottom and top of the wall's.
There is a think scale on the bottom of the pool and like a think scum mark on the wall tile's. I have tried to jet wash off with not much help could some one please advice me on the best way to clean the pool of scum before I start to re-grout..

Thank You


User: Inyopools

remove calcium - Your pool filter cannot remove calcium in your water. You will have to drain part of your pool and replace it with fresh water. If you have very hard water in your area, you might consider installing a water softener.


Hi. I just used a razor to remove high calcium buildup on the pool tile, it was thick and scraping was the only way to remove it. The pool has not been open since sept, so there is no chemicals added yet. To lower the calcium level now, can I run the filter for awhile? OR do I have to drain half the pool?? I would rather not have to drain any water.

User: Inyopools

calcium deposits - Your first step is to get your pool chemicals in balance. Take a sample of your water to a local pool store and have it tested. They will print out what is out of range and list what chemicals to add to correct your problems. Most likely your hardness and pH are too high. If your hardness is above 400, you will have to dump some of your pool water and replace with fresh to reduce the hardness level. This will stop calcium deposits and reduce calcium buildup. You may have to brush the bottom of your pool to work the existing calcium off.


I have calcium deposits on the bottom of my pool. The pool has gray plaste. How do I remove the calcium from the deep end of the pool?

User: Inyopools

bitz - Your rough surface is probably calcium which probably means your pool's hardness level is too high. Take a sample of your pool's water into a pool store and have them test the chemical levels of your pool. All chemical should be in balance but pH, Alkalinity and Hardness and critical to resolve this problem. Follow their instructions on what chemicals to add to get your pool in balance. If your pool's hardness level is above 400, you will have to dump some of your pool's water to reduce it to 350 for a little buffer. If the calcium buildup on your pool liner is severe, you may have to replace the liner.

User: bitz

I have a rough raspy build up of some sort on the pool bottom and sides of the liner under the water level. Where did it come from and how do I clean it off?

User: Inyopools

Calcium Deposits - I would apply the Tile & Vinyl Cleaner on the water line with a long handled sponge, let it sit, and brush it off with your pool brush. Follow detailed instructions on the bottle. I would not leave the calcium deposits on too long. As soon as they are obvious, balance your pool chemicals and remove the deposits. The longer they are on your pool surfaces, the harder they will be to remove and the greater chance they will cause permanent damage.


How long can the calcium sit there before damage can occur to the pool?


Can this be done without having to get in the pool?

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Tips & Warnings

Make sure that the pump and filter are running whenever chemicals are added to the pool.

Please Note:

Inyo Pool Products is not responsible for any injury or damaged equipment
while using our guides. Using our guides is doing so at your own risk.
These guides are suggested use of your pool or spa equipment and may vary
depending on which product you are using.