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Calcium is the most complex and difficult of all the pool stain issues we treat because calcium can form in a pool for a variety of reasons.

White calcium (or scale) can form because pool owners often have difficulty keeping their pH in balance – particularly when their pool is new. High pH is a major reason for calcium formation and growth.

Calcium spots can also form due to poor interior application when the pool surface is being applied in a new or renovated pool. Poor application can leave air bubbles or voids in the concrete finish. These voids soon fill with water which then calcifies. Then, as the calcium in the void continues to expand over time it pushes calcium out through the interior and into the pool. This is referred to as a calcium nodule.

Calcium scale is another common issue in concrete pools as many coloured pool surfaces now use white cement instead of grey. White cement contains around 36% calcium hydroxide which contributes to the challenge of managing calcium. Once a thin layer of calcium has formed, it continues to grow because it attracts more calcium to it over time. Eventually the calcium will become bigger and sometimes harder than the concrete pool surface!

If you have calcium spots or scale we strongly recommend you do something about it soon. Calcium that is left untreated can lift, crack and break up your cement pool surface over time causing serious and costly damage to your pool. Sadly we often inspect pool surfaces that are almost completely destroyed by several hundred large calcium spots that have been left to grow. Our treatments can help prevent this from happening to your pool.

Typical signs of calcium scale and spots

  • White stain/lump that won’t brush off
  • White hard film on the pool surface
  • White lumps that are growing, very hard & multiplying
  • White ‘icicles’ that run down the walls of the pool

We remove calcium without draining your pool

The good news is that our treatments almost always remove calcium marks completely without draining the pool or acid washing. Our proven treatment process is very effective in treating and removing calcium stains from Pebblecrete, Quartzon, vinyl lined and fibreglass pools. We also have prevention products to help it stay away once it is removed.

We do not recommend acid washing to remove calcium. Although this process often removes it initially, the challenge is that the calcium build-up will very often return within a few months if the water is not treated with calcium preventative. The good news is that our treatment is a fraction of the cost of an acid wash and more effective. This is because we add the needed preventives to the pool as part of the treatment. For more about acid washing click here.

If you are unsure of the type or cause of your calcium issue please feel free to call us first.

OPTION 1 – Calcium Stain Removal DIY kit

What We Do 1


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  • 1 Litre of our powerful calcium release and prevention formula
  • 4 Kgs of our granular calcium dissolving compounds custom made for your stain
  • Phone support from our technicians
  • Simple step-by-step instructions included
  • Pool does NOT need to be drained
  • Kit is sent and electronically tracked by Fastway Couriers
  • Kids are back in the pool in just 7 days
  • Kit is $275 for pools 45,000+ Litres


Enquire now!

OPTION 2 – Calcium Removal – On Site Technician


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  • 1 Litre of our powerful calcium release and prevention formula
  • 4 Kgs of our granular calcium dissolving compounds custom made for your stain
  • Pump, filter and chlorinator inspection
  • Surface inspection and stain diagnosis
  • Complete 7 point on site water testing
  • Your pool does NOT need to be drained
  • Kids are back in the pool in 7 days
  • Visit is $395 for pools 45,000+ Litres


Enquire now!

Our Company Credentials

SPASA members for complete peace of mind.


Certified technicians all with at least 7 years experience.

Approved contractors for commercial and public pools.

We carry $5 million in insurance for your protection.

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Main forms and causes of calcium formation

1) Hard white balls/spots approximately the size of small round bean bag filling (approx. 2 – 6 mm in diameter) that appear randomly over the walls and floor of your pool and are difficult to brush away. These are sometimes referred to as calcium nodules. This often occurs when a void of calcium rich water under the pool surface pushes calcium into the pool. Sometimes these nodules form because of poor surface installation techniques. See diagram.

2) White calcium icicles (nodules) (approx. 2 – 3mm wide and 3 – 12mm long) can appear to be ‘growing’ out of the walls or floor of your pool. This type of calcium formation may indicate that a section of the pool surface has delaminated (pushed out) from the main pool structure. If the calcium spot reappears in the same place after cleaning, delamination is likely to be the main cause. Please call us if you suspect you have calcium nodules, surface cracking or white calcium spots in your pool. This type of calcium build-up is often more noticeable in darker coloured interiors.

3) Brown cloudy stains are often caused by calcium carbonate capturing either dirt, metals or copper as it forms its crystalline lattice structure. Calcium can appear in the form of a thin calcium film that covers dirt or metal stains on the pool interior. Although calcium carbonate is always white, in this case, it presents as brown or grey because the dirt discolours the calcium carbonate making it appear brown. This discoloured calcium cannot be removed with traditional treatments such as chlorine or firm brushing because the calcium carbonate film over the surface ‘shields’ the stain underneath.

4) Calcium can form cloudy white blotches or swirl marks on the bottom of your pool. When this calcium has formed, it will leave a light white film on the surface of the pool that will highlight the imperfections in the pool surface. Sometimes our clients will say that their pool looked great when it was first filled, but later on they can now see swirl marks, ridges or trowel marks that have appeared a short time later.

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Why Choose Us?

Because you can speak to a stain specialist about your pool stain today. There is no cost or obligation and we are happy to look at pictures and talk with you before we come out or send a kit. Email pictures to or call us.

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