SCALING

Calcium scaling in swimming pools can be a frustrating issue, but understanding its causes and knowing how to address it is essential for pool maintenance and the establishment of staining to the surface of the pool. Let’s dive into the details:

Types of Calcium Scaling:

Calcium Carbonate: This is the more common type of scaling. It forms white deposits on pool surfaces, such as walls, railings, and ladders. While it can be challenging, it’s manageable.

Calcium Silicate: This type forms more slowly and is extremely difficult to remove. If you suspect calcium silicate buildup. It may also indicate pipe buildup.

Calcium Nodules: Calcium nodules in swimming pools are small, hard deposits that form on the pool surface, often resembling tiny white or grey bumps.

To differentiate between the three, apply a drop of muriatic acid to the scaling. If it reacts and foams, it’s calcium carbonate; if not, it’s likely calcium silicate.

Causes of Calcium Scaling:

High Calcium Levels: Water with calcium levels above 400 ppm (parts per million) can lead to scaling. Hard water areas are prone to this.

Water Chemistry: High alkalinity and pH create an ideal environment for scaling.

Water Temperature: Warm water exacerbates scaling.

Causes of Calcium Silcate Scaling:

Calcium silicate scaling in swimming pools is caused by a combination of factors:

At the time the pool surface is laid down: May be linked to the amount of silicate used in the mix and ingnoring the water chemistry protocols and surfce brushing for the first month after being filled with water.

High calcium levels: This can be due to hard water or the use of calcium hypochlorite shock, which adds calcium to the water.

High alkalinity and high pH: These create the perfect environment for calcium scaling.

High water temperatures: Elevated water temperatures can also contribute to calcium scaling.

Causes Calcium Nodules:

In swimming pools are small, hard deposits that form on the pool surface, often resembling tiny white or grey bumps. These nodules are typically caused by an excess of calcium carbonate in the pool water, which accumulates and solidifies on various surfaces. Let’s explore the reasons behind calcium buildup in pool interiors:

Calcium Carbonate Scaling Calcium Nodules

Calcium Silicate Scaling Chemicals Used

Calcium Scaling:

Following are treatments used by Billabong Pool Service to address the extremely difficult issue of calcium carbinate scaling. When addressing the provision of treatments for this type problem, the service person needs to seek out the following before contmplating providing a treatment.

The severity of the outbreak, the length of time the outbreak has been allowed to go untreated.
The type of outbreak, the environment around the pool.
The sanitation equipment and the filtration equipment.
The current water chemisty.

Calcium Carbonate Scaling

here are some examples of scaling

The common approach is to use chemical treatments to dissolve calcium carbonate deposits but, one or all of the following treatments may need to be used to address this issue.

Consider adding a chemical sequestrant to the pool water. This helps prevent the formation of new deposits and may even reduce existing ones.
Lower Calcium Hardness: Partially drain and refill the pool water to reduce calcium hardness.
Manual Removal: Scrub the scaling using a pumice stone or a stain eraser tool.

Chemical Treatment:

Establish the water chemistry and if possible the water chemistry history of the pool.
The parameters to consider are pH and T.A. (Total Alkalinity) as they are the most important in proceeding with a treatment.
A target of pH 7.0 and a T.A. under 100ppm but no less than 60ppm. Consider an acid bath with water in-place at this stage if you feel the severity of the scaling justified, at a rate of 10lt of undiluted acid per 50,000lt (be aware that this will drastically reduce both pH and T.A. and should only be used for a short period of time 24hrs to a maximum of 48 hrs only to soften the deposits and after that period a less agressive pH and T.A. level should obtained)
Calcium Hardness level should be established to provide a base point and recorded, and will be referenced after treatment has been performed.
To soften the scaling the use of products like Lo-Chlor Stain and Scale Attack parts 1 & 2 have proved effective in softening and subsequently the removal of light to moderate scale.
Heavy scaling may require multiple treatments and more aggressively low pH levels for prolonged periods of time, weeks, possibly months.
Manual Removal: Scrub the scaling using a pumice stone, stain eraser sticks and or metal algae brush to help loosen the soften scale.*
Testing of calcium hardness needs to be performed at this stage to establish that calcium level has increased from the base point established before the treatment started.This will indicate the removal of calcium from the surface, and the success or failure of the treatment.
A sequestering agent like Lo-Chlor Stain & Scale Defence, Lo-Chlor Aquaguard or Riversands CalStop to retain the removed calcium in solution.
Filtration should be addressed at this time and a regular filer clean schedule of every 2 days should be in place at least a week after treatment.
If a cartridge filter is being used the condition and effectivness of the filter needs to be assessed and replacement may need to be considered.
If a sand filter is in use you should consider the use of Lo-Chlor Filter Aid & Metal Remover.Partially drain and refill the pool water to reduce calcium hardness may be required in extreme levels of calcium hardness.
Re-balance pool and continue to monitor calcium hardness levels and continue removal protocols until it reaches between 180ppm to 250ppm

* The use a pumice stone or a tile brush to gently remove the scaling from pool walls, tiles, and other surfaces.
Be cautious not to damage the pool finish while scrubbing.

Calcium Silicate Scaling

Calcium silicate forms much more slowly than calcium carbonate, another type of scaling. Once it’s there, it’s nearly impossible to remove, as the crystalline matrix is much tighter and harder than calcium carbonate and may not even react to direct undiluted acid application.

Even worse, if you have calcium silicate, there is a very good chance that you also have buildup in your pipes.

For a calcium silicate buildup. The most obvious option for this type of scaling is for the customer to cut their losses and resurface the pool.

If the customer is not in a position to re-surface the pool, or would like other options. The following control only measures may be offered:

It’s important not to let a calcium silicate build up or continue to build up for too long, as it will eventually damage your pipes and your filter.

You could use the same chemical the same treatment approch as for calcium carbonate scaling, don't expect full or even partial eradication. What it may do is remove some surface scaling recent plated down

Consider adding a chemical sequestrant agent like Lo-Chlor Stain & Scale Defence, Lo-Chlor Aquaguard or Riversands CalStop to retain the removed calcium in solution. This helps prevent the formation of new deposits and may even reduce existing ones.

Consider reducing pH and T.A. parameters closer to a fibreglass pool pH to 7.0 T.A. to maximum of 80ppm permenatly.

Reverse osmosis treatment can also be beneficial in preventing calcium buildup on pool surfaces.

Reverse osmosis is a process that removes impurities from water by passing it through a semipermeable membrane.
Regularly using reverse osmosis treatment can help remove excess calcium from the pool water, preventing buildup on pool surfaces.

Calcium Nodules

You may find the following links help in explaining nodules

Calcium Nodules on swimming pool plaster Pt 1

Calcium Nodules on swimming pool plaster Pt 2

Calcium nodules in swimming pools are small, unsightly bumps composed of calcium carbonate that can form on plaster, fibreglass, or tile pool linings. They typically result from a poor plastering job or normal ageing in older plaster pools. When air bubbles become trapped in dried plaster, it leads to delamination of the pool lining, allowing elements of it to become exposed to the pool water. Loose or Drummy Surface: If the pool surface becomes loose or develops voids, water can seep behind the pebbles or other materials. Calcium hydroxide may then bleed into the water, leading to the creation of calcium carbonate nodules along the surface.cium hydroxide in the pool lining to combine with alkaline elements in the water, forming the calcium nodules

To remove calcium nodules, you can scrape them off with a stiff trowel, but this is only a temporary fix as they will likely reform. The only true solution is to repair or replace the pool’s lining. Formation InHigh pH in the Pool Water: When the pool water has an elevated pH level, it can contribute to the formation of calcium nodules. Maintaining the correct pH balance is crucial to prevent this issue.

Very High Calcium Hardness: Proper calcium hardness levels are essential for protecting the pool surface from calcium-related problems. For pebble, quartz, and glass bead pools, the suggested calcium hardness level is 200-250 ppm. Fiberglass pools vary by manufacturer, but most recommend a minimum of 150 ppm.side the Surface: Sometimes, calcium nodules form within the pool surface itself. These stubborn calcium deposits often appear as hard white scales on the pool surface.
To prevent calcium buildup, focus on maintaining the right pH and alkalinity, and ensure proper water balance. While some treatments temporarily reduce the effects of high calcium, they don’t permanently remove calcium buildup. Keeping the water chemistry balanced is key to avoiding calcium-related issues in swimming pools.

Chemical Treatment:

Establish the water chemistry and if possible the water chemistry history of the pool.
The parameters to consider are pH and T.A. (Total Alkalinity) as they are the most important in proceeding with a treatment.
A target of pH 7.0 and a T.A. under 100ppm but no less than 60ppm. Consider an acid bath with water in-place at this stage if you feel the severity of the scaling justifies, at a rate of 10lt of undiluted acid per 50,000lt (be aware that this will drastically reduce both pH and T.A. and should only be used for a short period of time 24hrs to a maximum of 48 hrs only to soften the deposits and after that period a less agressive pH and T.A. level should obtained).
Calcium Hardness level should be established to provide a base point and recorded, and will be referenced after treatment has been performed.
To soften the scaling the use of products like Lo-Chlor Stain and Scale Attack parts 1 & 2 have proved effective in softening and subsequently the removal of light to moderate scale.
Heavy scaling may require multiple treatments and more aggressively low pH levels for prolonged periods of time, weeks, possibly months.
Manual Removal: Scrub the scaling using a pumice stone, stain eraser sticks and or metal algae brush to help loosen the soften scale.*
Testing of calcium hardness needs to be performed at this stage to establish if the calcium level has increased from the base point established before the treatment started.This will indicate the removal of calcium from the surface, and the success or failure of the treatment.
A sequestering agent like Lo-Chlor Stain & Scale Defence, Lo-Chlor Aquaguard or Riversands CalStop to retain the removed calcium in solution.
Filtration should be addressed at this time and a regular filer clean schedule of every 2 days should be in place at least a week after treatment.
If a cartridge filter is being used the condition and effectivness of the filter needs to be assessed and replacement may need to be considered.
If a sand filter is in use you should consider the use of Lo-Chlor Filter Aid & Metal Remover.
Partially drain and refill the pool water to reduce calcium hardness may be required in extreme levels of calcium hardness.Re-balance pool and continue to monitor calcium hardness levels and continue removal protocols until it reaches between 150ppm to 250ppm.

* The use a pumice stone or a tile brush to gently remove the scaling from pool walls, tiles, and other surfaces.
Be cautious not to damage the pool finish while scrubbing.

Chemical Used

Hydrochloric Acid

With an initial measured pH range of 7.4 to 7.6 work on 10lt per 50,000lt pool to achieve a pH of no more than 6.0. More acid will be required if intial pH level is higher than the above range.

Stain & Scale Attack pt 1

Concentrated calcium scale remover
Can also be used as an effective copper stain remover.
Lo-Chlor Scale Attack works best at pH 7.0. Make sure the Chlorine level is below 1.0 p.p.m. High chlorine levels will neutralise Scale Attack
Lo-Chlor Scale Attack works very slowly. Advise the pool owner it will take up to 6 weeks before results are sometimes seen.

Stain & Scale Attack pt 2

Stain & Scale Defence

A calcium scale inhibitor for the prevention of scale build up on pool surfaces. An anionic, non-phosphate dispersant and scale inhibitor used to reduce scale formation, iron staining, corrosion of pool heating equipment, scum deposits and plugging of filters. It also acts as a sequestrant which will retain removed calcium in solution and allow it to be filtered out. It should be used in conjunction with Stain & Scale Attack.

Cal Stop

It’s important to control Calcium levels to ensure proper water quality and maintain the beauty of your
pool. High pool water calcium hardness levels, especially
above 400 PPM, can sometimes reduce the clarity of water
and cause scaling issues. Use Cal-Stop to inhibit the formation of calcium scale in salt and freshwater pools and maintain their great look. It also acts as a sequestrant which will retain removed calcium in solution and allow it to be filtered out.

Aquagaurd C.S.M

Is a versatile and multi function speciality product that can be used for a diverse range of solutions to enhance the quality of your pool surrounds, your pool equipment and your pool water. Keeps scale at bay by both ASSISTING IN THE REMOVAL of existing scale and INHIBITING the build up of scale from pool walls, equipment and pipes. It also acts as a sequestrant which will retain removed calcium in solution and allow it to be filtered out.

Calcium Hardness Reducer

Hydroxyethylidene Diphosphonic Acid Complex.

Reduces calcium levels to the ideal range of 200-400ppm. It will restrain calcium scale formation on pool and spa surfaces as well as valuable equipment. It will restore water clarity on application.
What advantages does it have over other similar products? Lo-Chlor Calcium Hardness Reducer is a made with highly concentrated liquid formulation. It is compatible with all recognised sanitisers and other pool and spa additives It may be used in all types of pool and spa finishes.
It is easy to use It is economical to purchase. There is no residue so no need to vacuum pool to waste. It also acts as a sequestrant which will retain removed calcium in solution and allow it to be filtered out.

p.H. Increaser

It acts as a sequestrant which will retain removed calcium in solution and allow it to be filtered out.

However, it’s important to use soda ash correctly to avoid issues like cloudiness in the pool water. If you’re considering using soda ash for calcium sequestration, it’s advisable to determine the appropriate amount for the pool volume and method for your specific pool conditions.

Metal Solution

Although not specifially for this use, but can be also used as a sequestrant.