Why Scale Forms On Pools And How Can You Remove It?

Even if the water in the pool looks clean, there might be a stubborn buildup of white or gray substance on the waterline, tiles, or other pool fittings. This mineral accumulation is referred to as “pool scale,” and it is a very common pool maintenance problem that negatively affects the appearance of your pool.

Pool scale is formed due to mineral concentration in the water or an imbalance in the water chemistry. Fortunately, you can avoid its formation if you conduct timely water tests, maintain the water balance, and use the appropriate cleaning technique.

In this guide, we will describe the formation process of the pool scale, ways to distinguish between various kinds of deposits, methods for removing the build-up of calcium, and measures for maintaining the pool.

What Is a Pool Scale?

The pool scale is an insoluble mineral deposit that occurs when minerals dissolved in the water of the swimming pool precipitate on the pool surfaces. Calcium carbonate is a frequent source of deposits; however, there might be some other sources of particular kinds of deposits.

Unlike soil and algae, the pool scale sticks strongly to the surfaces of the swimming pool. It forms a chalky layer, which becomes harder and harder to get rid of with time. Scale is commonly found in the following places:

• At the waterline of the tiles and liners of the pool
• On the steps, ledges, and other underwater surfaces
• In and around return jets, ladders, and metal fixtures
• On the spillways, water features, and splashed areas

A little scale formation may not cause any trouble at first, but heavy formations may impact the aesthetic of your pool and make it difficult for certain pool fixtures to work properly.

What Causes Scale to Form in Swimming Pools?

Knowing the reason for the formation of scale is a good starting point in getting rid of it and making sure that it doesn’t appear again.

1. High Calcium Hardness

Calcium hardness shows how much dissolved calcium there is in your pool water. While calcium is an inherent chemical component of pools, too much of it may cause calcium buildup, especially if the pH or alkalinity is too high. As the water stops dissolving so much calcium, mineral deposits may start forming.

What to do: It is necessary to regularly check the level of calcium hardness and compare it with the recommended level based on the characteristics of the surface and technical equipment of your swimming pool. In case the level is too high, seek help from a professional to correct it.

2. High Pool Water pH

pH influences the chemical composition of water in a swimming pool. With increased pH, the likelihood of scale formation increases due to the precipitation of calcium carbonate from the water. Increased pH happens due to various factors such as regular chemical treatment, aeration, etc.

What to do: Monitor the pH frequently and keep it in the correct range for your swimming pool and sanitizing system. In most conventional pools using chlorine, the standard level is 7.2-7.8, but you must follow the instructions given on products and equipment.

3. High Total Alkalinity

Total alkalinity works to stabilize the pH of pool water. Yet, if total alkalinity is excessively high, it can make the pH unmanageable and lead to calcium scale formation.

What to do: Total alkalinity should be measured together with pH and calcium hardness. Don’t make changes in one chemical parameter without paying attention to the others.

4. Water Evaporation and Mineral Concentration

Water evaporates from the pool, but usually, the dissolved minerals do not go away with it. This is because, as water evaporates, the concentration of calcium and other dissolved components may increase. This phenomenon is evident near the water line, which becomes covered with mineral deposits.

Refilling the pool with fresh water replenishes the missing water but not necessarily removes the minerals that have been built up over time.

What to do: Maintain proper water balance and pay special attention to the calcium hardness levels if the refill water is high in minerals.

5. Warm Water and Water Features

Warm water, aeration, and continuous splashing are ways to facilitate the environment where scale is more likely to develop. The splashing from fountains, spillways, waterfalls, and other structures will release CO₂ from the water into the air, thus leading to the increase in pH. An increased pH level will allow calcium carbonate to precipitate.

What to do: Increase the frequency of checking your pool’s pH level if your pool has any water feature that is active for long durations of time.

How to Identify Calcium Scale in Your Pool

Not all white spots on pools are calcium deposits. Correctly identifying the source is important for finding a suitable solution to the problem without scratching your pool.

Here are some symptoms of mineral deposits:

• White or gray spots: White, chalk-like deposits can occur in various places such as tiles, steps, etc.
• Crusty water line: Where the water meets the wall of the pool can become crusty.
• Difficult-to-remove spots: Mineral deposits tend not to respond well to regular brushing and cleaning.
• Deposit spots around fittings: Such spots can occur around return jets, ladders, and other spots with splashing water.

Usually, scale is rough and scaly, oils are slick, and organic stains can be other colors or patterns. Nonetheless, just looking at something does not tell you what it is. If you cannot identify the build-up, check your water and have an expert inspect your surface.

How to Remove Calcium Scale From Pool Surfaces

The best removal method depends on the type and thickness of the deposits and the pool surface you need to clean. There are cleaning methods that can work effectively with ceramic tiles, but they may harm vinyl liners and plaster surfaces. Before cleaning, make sure you know the surface type and read the directions of the chosen cleaning agent.

Step 1: Test and Balance the Pool Water

First, check the pH levels, total alkalinity levels, and calcium hardness. This will help you understand the conditions that led to the accumulation.

It is vital to fix the water chemistry, as removing the scales without addressing the problem will lead to further scale accumulation.

Always follow the guidelines provided with your pool products and equipment. Never combine multiple products together and adjust the quantities inappropriately.

Step 2: Brush Away Loose Deposits

Make use of a pool brush that will match your pool surface to get rid of the dirt and loose scale. In case of delicate pool surfaces, it is advisable to use a soft brush to prevent scratching of tiles, liners, or wearing away of pool surfaces.

Step 3: Clean Waterline Deposits

When the problem is light stains on tile, choose a specially formulated calcium or waterline cleaner for pools that is suitable for your particular type of tile.

Use the product following the instructions on the label, using the recommended brush or cleaning pad. Follow rinsing directions and take care to keep concentrated cleaning products out of the pool unless the label says it is okay to do so.

Do not just assume your household cleaning products are safe for use in the pool. Products that contain acids or abrasives may be harmful.

Step 4: Treat Stubborn Calcium Deposits

A hard, calcified scale might need special descaling agents or heavy-duty cleaning tools. Some pool experts employ abrasives or other methods for dealing with deposits without causing unnecessary damage to the surface. The type of surface (ceramic tiles, natural stone, plaster, fiberglass, or vinyl) determines how to treat the deposit.

Avoid using any metal tools, abrasive substances, or acidic cleaners. These may scratch surfaces, ruin grout, cause corrosion of the fixtures, and damage other surfaces. In case of heavy deposits or scaling, it will be better to seek professional help for pool cleaning.

Step 5: Retest the Water After Cleaning

After cleaning is done, test the pool water again to restore its proper balance of chemicals. In case the cleaning product is one that has the capability to affect the chemistry of water, follow its directions on how to rinse, filter, retest, and use the pool again. Getting rid of the scaling alone is not enough; keeping the water balanced will prevent another layer from forming.

How to Prevent Calcium Scale From Returning

Often, prevention is less difficult than trying to get rid of large accumulations. Routine maintenance practices will help keep mineral deposits in check.

Test Pool Water Regularly

Test for pH, total alkalinity, and calcium hardness on a consistent basis. Increase testing frequency during those times when water conditions change due to weather, pool activity, or any water features present. Documenting the results will allow you to track patterns rather than waiting until scaling occurs.

Maintain Balanced Water Chemistry

Maintain your pool water levels as suggested for your type of pool surface and sanitizers. In this case, be cautious of your pH and calcium hardness levels because when combined, they affect the chance of forming calcium carbonates. The best way would be to consult a pool expert on the matter.

Control Calcium Buildup in Fill Water

If your source water has a high mineral content, refilling may lead to an increase in hardness due to calcium. It is necessary to check the filling water if the scale occurs repeatedly. Based on the test results, an expert will advise on an appropriate treatment for water or even a partial water change.

Do not drain a pool without considering the manufacturer’s recommendations and the conditions in your area, as there are risks associated with draining some pools.

Brush and Clean the Waterline

Clean your pool’s waterline before a buildup of deposits forms that is hard to clean. Brushing your waterline on a regular basis and dealing with a small deposit will help you avoid needing a lot of descaling. Use brushes and other cleaning equipment appropriate for your pool’s surface type.

Monitor Water Features and Splash Zones

Aerating devices like waterfalls, fountains, and spillways may lead to increasing pH levels due to aeration. In case you have frequent deposits of scale near these aerating devices, consider checking the pH level and balance instead of focusing on surface cleaning alone.

Can Pool Scale Damage Your Swimming Pool?

While pool scaling is not usually a problem for the structural integrity of the pool right away, ignoring significant scaling can lead to maintenance issues.

These deposits can:

• Cause surfaces such as tiles to become coarse.
• Cause the waterline to be stained or unkempt.
• Form around fittings and other water features.
• Make it harder to clean.
• Cause mechanical issues once deposits form in vulnerable parts.

The impact depends on the deposit’s nature, location, and the pool’s condition. It may be that a regular cleaning of the surface is not enough and that a professional examination is needed to deal with the deposits in pipes or heaters.

When Should You Call a Professional Pool Cleaning Service?

While some deposits can be effectively treated with normal brushing and a proper pool cleaning agent, others require a bit more care.

You may want to seek professional advice if:

• The scale is extensive.
• The deposits are dense, hard, or difficult to identify.
• Earlier attempts at cleaning failed.
• Your pool has sensitive materials or natural stones.
• It is difficult to keep calcium hardness or pH under control.
• There might be deposits in the circulation or heating systems.

The professional may be able to inspect the pool surface, test the water, choose an appropriate removal technique, and suggest a maintenance schedule to avoid future recurrences of this issue.

Keep Your Pool Clean With Professional Help

Even well-maintained pools can develop an appearance of neglect because of the buildup of calcium scale. The important thing about dealing with calcium scale is to find the cause, apply an appropriate cleaning technique, and keep proper water balance.

With testing, timely cleaning of the waterline, and proper maintenance of water hardness and pH levels, one can decrease mineral deposits.

Do you require assistance with handling difficult-to-remove residues or ensuring that your swimming pool stays in good shape? We at Perfect Pools of VA can assist you in maintaining a cleaner swimming experience.

Come visit us at Perfect Pools of VA to learn more about our pool cleaning and maintenance services. You can also request a free consultation or read our customer testimonials.

FAQs

1. What is the fastest way to remove calcium scale from pool tiles?
   A waterline cleaning product approved for pools and a suitable brush can be enough for light-scale buildups. A hardened scale would need a descaling process. The best way to clean the tile and grout is not straightforward to determine.
2. Does high pH cause calcium scale in pools?
   Increased pH results in the increased possibility of forming calcium carbonate scales, especially where there are high calcium hardness levels, among other aspects of water balance. Proper pH levels are very critical in prevention.
3. Can I use vinegar to remove the pool scale?
   Vinegar is an acid that can affect light mineral deposits, but it cannot be used on all types of pool construction or scales. Additionally, vinegar could have an effect on the chemistry of the water. Use a product that is safe to use in the specific type of pool you have.
4. Will brushing alone remove calcium scale?
   Brushing might be able to loosen light buildups, but scrubbing will not be sufficient to remove thicker, adhered scale formations. Consider using an appropriate cleaner or seeking professional assistance if normal brushing doesn’t work.
5. How often should I check my pool water to prevent scale?
   Monitor water chemistry often based on your pool’s requirements. You may need more frequent monitoring during hot weather, after high usage periods, or when the pH tends to rise. Testing of calcium hardness is also recommended, especially if the fill water is rich in minerals. See our pool maintenance tips for a year-round routine.