Calcium on fibreglass pools
Calcium on your fibreglass Pool?
No Draining, No Acid Washing No Wasted Water!
20,000 Pools Transformed since 2013
If you have calcium buildup on your fibreglass pool we can remove it without damaging the gelcoat or draining the pool. Our treatment dissolves the hard white film and restores the smooth blue finish. We also include a preventative solution to stop teh calcium from coming back. Don’t delay because calcium left untreated will continue to spread and thicken, making the problem harder to solve.
Our treatment contains three active ingredients that work together to dissolve various types of calcium, including:
- Calcium carbonate
- Calcium hydroxide
- Calcium silicate
- Waterline calcium
Our products have no bleach or harsh chemicals, so they’re safe for use in fibreglass pools. In fact, several large fibreglass pool manufacturers in Australia have recommend our process for safe calcium removal for over 10 years.
White Calcium Scale on fibreglass pools
What is the cause of the white buildup on fibreglass pools?
- Very high pH – Calcium on fibreglass pools is often caused by unbalanced water chemistry. When pH, is very high, then calcium or minerals in the pool water will precipitate and bond to the pool surface.
- Calcium Based Chlorine – Some types of granular chlorine ‘cal-hypo’ is a blend of chlorine and calcium. This means that adding chlorine to the pool means you’re also adding calcium!
- High Calcium Hardness – many fibreglass manufacturers suggest maintaining a calcium hardness of 120ppm or less. This is much lower than a concrete pool. An overdose of calcium can lead to white scale on the surface.
When a rough, white layer forms on the surface often dirt and other minerals will also combine with the calcium. This is why some calcium scale can appear light brown or grey. Don’t worry, as the calcium dissolves, any brown stains that are bonded to the calcium will also dissolve away.
Why is my fibreglass pool turning white?
If you notice that your blue fibreglass pool looks white when the water drops, you’re not alone. Don’t worry, this is usually a thin layer of calcium that has bonded to the surface. Our treatment will:
- Dissolve the calcium away.
- Safe to use on all fibreglass pools.
- Removes white ‘haze’ and scale.
- Prevents calcium from returning.
Our calcium remover kit dissolved the tough calcium buildup on this dark fibreglass pool, revealing its original, smooth finish. High pH levels often cause calcium to precipitate out of the water, leaving behind a stubborn white film that becomes even more visible as the water level drops.
This customer with the black pool was convinced his pool surface had been bleached after trying multiple methods with no success. After 12 days after using our calcium treatment, the white layer was completely gone.
Please don't try to scratch it off
The gelcoat layer in fibreglass pools is very thin, around half the thickness of a credit card. So, abrasives will easily scratch and damage the surface. That’s why our treatment is engineered to gently dissolve calcium buildup over several weeks. It’s the safe way to remove calcium scale and bring back the smooth, clean finish of your pool.
Mineral Scale formation on fibreglass
Some of our clients have no choice but to fill their pool using bore water, which was very high in calcium, iron, and minerals. As a result, they constantly battle roughness and discolouration on the pool surface.
When water is oversaturated with calcium or metals, it often deposits a stubborn brown film that regular cleaning can’t remove. Our treatment fixes the issue without draining the pool.
Once the mineral and scale have been removed, protect the pool surface by applying our Scale & Stain Eliminator every six months to keep it smooth and looking great.
Calcium Removal Options
OPTION 1 Calcium Removal - DIY kit
- 1 Litre of our calcium prevention polymer
- 3.5 Kgs of our calcium dissolving compounds
- Phone support from our technicians
- Simple step-by-step instructions included
- The pool does NOT need to be drained
- Kit is sent and tracked by Aramex Couriers
- Kids are back in the pool in just 7 days
Most Pools $245
OPTION 2 Calcium Removal – On Site Technician
- 1 Litre of our calcium prevention formula
- 3.5 Kgs of our calcium dissolving compounds
- Complete 7 point on-site water testing
- Your pool does NOT need to be drained
- Kids are back in the pool in 7 days
- A technician may be an add-on for $170 once you've ordered the DIY Kit
From $415
Calcium Scale Remover Price List
| Water Volume | Kit Prices - Inc. GST & Delivery | What You Get |
|---|---|---|
| Up to 40,000 Litres | $245 | X 1 Bottle of SSE + 2 Bags of Calcium Compound |
| Up to 65,000 Litres | $295 | X 1 Bottle of SSE + 3 Bags of Calcium Compound |
| Up to 95,000 Litres | $345 | X 1 Bottle of SSE + 4 Bags of Calcium Compound |
| Up to 120,000 Litres | $395 | X 2 Bottles of SSE + 5 Bags of Calcium Compound |
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Frequently Asked Questions
How do I know if it is bleaching or Calcium? Is there a test?
Calcium indicators
Surface feels gritty and rough – A common indicator of calcium is that the surface under the water feels rough. Sometimes you can scratch small areas away with your fingernail.
Surface looks much better wet – Calcium scale will usually look ‘almost normal’ when the water level is high. However, when the water level drops, the white calcium really stands out. If is often when the water level drops that clients first notice the calcium formation.
The surface above the waterline looks better than the gelcoat underwater – Gelcoat is resistant to UV light so fading from the sun is minimal. However, when gelcoat is underwater, it is is a different story. Calcium and unbalanced water can make a huge difference to the appearance of the pool.
Bleaching indicators
The white discoloured surface feels very smooth – A common indicator of beaching is that the surface feels almost the same everywhere, even in areas where the colour is normal.
Surface looks pretty much the same – wet or dry – When the blue colour pigment has been oxidized by poor water balance, it means that the colour is basically dissolved. This means that even if the surface is wet that the colour barely changes.
A history of very high chlorine levels or very bad water balance – If you noticed that the surface turned white soon after the chlorine levels in your pool were very high for a long time this may be a indicator of bleaching. NOTE: Check with us first as calcium can also form in these conditions.
Do I have to drain my pool to do the treatment?
No, you do not have to drain the pool. The products works with the original water still in the pool and the prevention product also stays in the water to stop calcium from coming back.
What if my pool is bleached?
Is my pool bleached?
Thankfully bleaching is not very common in fibreglass pools but we do see it from time to time. If you think your pool is bleached please feel free to email us a picture of the pool and we can inspect it for you at no cost.
Our treatments can sometimes help with surface bleaching. However, there are often cases where nothing can remove the visual effects of pool surface bleaching. Please contact us for further information if you feel your pool may have this issue.
There are resurfacing options for pools that are bleached. These include epoxy paint and Ecofinish. Both of these products can be applied to fibreglass pools and look as good as new.
Pool Cover Warning
Saltwater chlorine generators add free chlorine to the pool when they are running. So if you cover the pool and the water is protected from sunlight then the chlorine levels will continue to rise. This means that the free chlorine levels can rise to dangerous levels quickly. We’ve seen many cases where the free chlorine has exceeded 40ppm in these situations. So, if you’re covering your pool, make sure you reduce the chlorine production significantly. Remember:
- Your pool will not use much chlorine when the cover is on.
- Very high chlorine levels can bleach your fibreglass surface.
Notice that even with the hose in the water that the surface does not change colour. This pool surface is bleached.
Protect your fibreglass surface
In fibreglass pool maintenance, sequestration is a critical defense. Unlike concrete pools, fibreglass relies on a thin, porous layer called gelcoat. So, when water becomes over-saturated with minerals, these calcium ions seek a place to deposit. If there is no sequestering agent, these ions will “dock” within the microscopic pores of the gelcoat, leading to a permanent, white hazy look that look like fading.
Our High-quality sequestering agent Scale & Stain Eliminator, works by chemically “dispersing” calcium and metal ions. This process, known as sequestering, keeps the minerals in a liquid state, preventing them from crystallizing on the pool walls. Because mineral deposits cover fibreglass pigments, consistent sequestration preserves the vibrant color and smoothness of the finish. By keeping the calcium “suspended”, you ensure the pool remains easy to clean and looking new.
Causes of discolouration in fibreglass pools
(Click headings below to view)
Calcium build-up on the pool surface
Why calcium forms on fibreglass
High pH levels – If your pH is too high, your pool water may cause soluble calcium to precipitate onto the pool surface. When this happens, it often leaves a thin white gritty layer on the fibreglass surface. As the picture shows, this white layer becomes very noticeable if the pool water drops below its normal level.
High Calcium Hardness – To help prevent calcium formation, test the pH and calcium hardness levels in your pool water. High calcium (above 400ppm) can often occur if too much calcium has been added to the pool. When this happens, it leads to calcium formation.
Calcium based granular chlorine – Calcium-based granular chlorine (cal-hypo) will also increase the calcium hardness levels in your pool. If your calcium levels seem to be rising for no reason, then it is likely that calcium hypochlorite is the cause.
Ask your pool manufacturer before adding calcium – Before adding any calcium chloride to your pool water, contact your pool manufacturer (not your pool shop) and get the suggested calcium levels for your pool. Each fibreglass pool manufacturer recommends different calcium levels so double-check that your pool shop is aware of the correct level. Also, make sure their computer knows that your pool is fibreglass and not pebble because pebble pools require different water chemistry settings.
Covering Salt Pools in Winter
Saltwater chlorine generators add free chlorine to the pool when they are running. So if you cover the pool and the water is protected from sunlight then the chlorine levels will continue to rise. This means that the free chlorine levels can rise to dangerous levels quickly. We’ve seen many cases where the free chlorine has exceeded 40ppm in these situations. So, if you’re covering your pool, make sure you reduce the chlorine production significantly. Remember:
- Your pool will not use much chlorine when the cover is on.
- Very high chlorine levels can bleach your fibreglass surface.
This partially drained fibreglass pool shows white calcium formation. Notice how thick and widespread it has become along the walls when the water drops. This client didn’t do anything about it for a few years hoping it would just go away – it didn’t.
The pool interior is ageing
Fibreglass pools often pass through two phases as the surface begins to age. Firstly, it is normal for the blue gelcoat colour to slowly fade to white over the decades. This fading occurs because of chlorine, years of sunlight, and poor water chemistry, all age the surface. Remember, this slow colour loss, which often starts after 15-20 years, is normal. This is not a sign of a faulty pool interior or poor maintenance.
The second stage of ageing is when pools (25+ years old) start to develop a persistent fine white powder that appears when you brush the pool. This powder is a degraded gelcoat that has slowly broken down over time. This degrading gelcoat will eventually disappear in sections of the pool, revealing the lower layers of resin that are often dark brown. This surface breakdown is normal, particularly in high-use areas such as steps and ledges. Remember, the best way to extend the life of your fibreglass pool is to take care of the water.
This Fibreglass pool has a heavy layer of calcium formation on the surface. You can see that the areas where the calcium has flaked away that the gelcoat color is intact and not bleached.
The layers of a fiberglass pool
The diagram below shows how the layers of material are bonded together. These layers are sprayed on by hand in the factory. Notice that most of the thickness of a fibreglass pool comes from the structure and not the thin blue decorative layer on the surface.
This sectional diagram shows the layers of a fibreglass pool from top to bottom. Remember, the pool water can slowly circulate through the top surface layer of gelcoat. This allows the gelcoat to be affected by poor water chemistry.
As fibreglass pools age, the blue top layer of gelcoat is worn away. This reveals the lower layers of brown fibreglass. This is not a stain. It is the fibreglass structure of the pool called the shell.
Bleaching of fibreglass or Gelcoat
Is my pool bleached?
Bleaching in a fibreglass pool happens if the pH and the chlorine levels are both very high. If the water remains at this level for a while, it may slowly bleach the pool surface. Fibreglass pools resist bleaching from mild water imbalance under Australian Standard (AS 1838:2021). The chemical resistance test outlined in the standard is quite rigorous. In short, the gelcoat must be able to withstand more than 60-80 times the normal chlorine level for 24 hours without any colour loss. However, gelcoat cannot withstand very unbalanced water for long periods and sometimes it can result in permanent colour loss.
Gelcoat bleaching is often smooth to the touch and is non-responsive to cleaners and acids. In some cases, rubbing the surface with fine sandpaper can appear to remove this discolouration, causing some to conclude that they must have calcium. However, rubbing removes the bleached Gelcoat layer in your pool. Remember, sanding the Gelcoat will leave your pool more susceptible to future staining and reduce the life of your pool surface. Don’t sand your fibreglass with any type of abrasive, as this may cause permanent damage and may void your pool warranty.
Balanced water prevents gelcoat bleaching
Some pool owners forget about their pool during winter (or when it’s covered). Often these same pool owners are horrified when they eventually remove the pool cover and discover extensive areas of surface bleaching. Check your water during winter, even if you have the pool cover on.
Our treatments can sometimes help with surface bleaching. However, there are often cases where nothing can remove the visual effects of pool surface bleaching. Please contact us for further information if you feel your pool may have this issue.
Pool Cover Warning
Saltwater chlorine generators add free chlorine to the pool when they are running. So if you cover the pool and the water is protected from sunlight then the chlorine levels will continue to rise. This means that the free chlorine levels can rise to dangerous levels quickly. We’ve seen many cases where the free chlorine has exceeded 40ppm in these situations. So, if you’re covering your pool, make sure you reduce the chlorine production significantly. Remember:
- Your pool will not use much chlorine when the cover is on.
- Very high chlorine levels can bleach your fibreglass surface.
Possible Gelcoat reaction with the pool water. Notice the smoothness of the white film and the distinct separation between the vivid blue and white along the waterline.
Adding undissolved buffer to the pool
If an undissolved alkalinity increaser (aka buffer or sodium bicarbonate) is sprinkled directly into the pool, it can cause a stubborn white film to bond to the pool surface. So, to avoid this, ensure that the buffer is completely dissolved in a bucket of water before it is added to the pool. Remember, when buffer is first added to water it will start as milky white and then as it continues to dissolve, the water will become clear within minutes. After that, once the water is clear then go ahead and add the buffer to the pool.
Do not drain or acid wash a fibreglass Pool
In most cases, acid washing makes no lasting difference to the appearance of fibreglass pools. However, if you insist on draining the pool, use a licensed and insured professional to do this work. This is because your pool walls must be cross-braced and secured to prevent buckling and cracking when you release the water.
If your empty pool gets pushed up through hydrostatic ground pressure, you’ll need the contractor’s insurance to pay for a new pool because you cannot just push the pool back down.
Please don’t drain a fibreglass pool, it’s never a good idea.
