Calcium is the hardest type of issue we treat each day because it forms in a pool for a variety of reasons. Most commonly, calcium appears because pool owners often have difficulty keeping their pH in balance – especially when their pool surface is new. High pH is a major reason for calcium formation and growth.
Calcium spots can also form due to poor pool interior application.
For example, when the pool surface is being applied to a new or renovated pool, poor plaster 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 the calcium out through the interior and forms a calcium lump on the pool surface. This white lump (sometimes look like an icicle) is a calcium nodule. Calcium can also enter the pool through fine cracks in the pool plaster that release calcium from the pool structure into the pool.
You don’t have to drain your pool to remove calcium deposits. Our treatments remove almost any calcium buildup in pool surfaces. Our proven treatment process is very effective in removing and preventing calcium deposits from Plaster, Quartz, vinyl lined, and fiberglass pools. We also include long-lasting 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 is more effective. This is because we add the needed preventives to the pool as part of the treatment. To learn more about acid washing click here.
If you are unsure of the type or cause of your calcium issue please feel free to contact us first.
On the other hand, many light colored pool surfaces now use white cement instead of traditional grey cement to achieve the desired color. This white cement contains around 36% calcium hydroxide which contributes to the challenge of managing calcium. This white cement can cause a thin layer of calcium to appear which continues to grow. This build-up will attract more calcium to it over time. Eventually, the calcium will become bigger and sometimes harder than the concrete pool surface!
If you have a calcium build-up in your pool 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.
If you have a calcium buildup in a fiberglass pool, we have a page dedicated to removing calcium from fiberglass pool surfaces here.
These are approximately the size of a small ball bearing (approx. 1/4 inch n 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. In other words, these nodules form because of poor surface installation techniques. See diagram.
Most commonly, there are approx. 1/4 inch wide and 1-2 inches long and can appear to be ‘growing’ out of the walls or floor of your pool. This type of hard white formation may indicate that a section of the pool surface has de-laminated (pushed out) from the main pool structure. If the calcium spot reappears in the same place after cleaning, de-lamination is likely to be the cause. Please call us if you suspect you have calcium nodules, surface cracking or white calcium spots in your pool. This type of build-up is often more noticeable in darker colored interiors.
When dirt or metals are captured by precipitated calcium carbonate, it will leave a dirty colored stain that will not brush away. Sometimes this can also turn calcium lumps a light brown rather than white. This happens because the calcium has become contaminated by the dirt and minerals in the pool. IN some cases, calcium can appear in the form of a thin calcium film that covers dirt or metal stains on the pool interior. Therefore, this type of staining cannot be removed with typical brushing or chlorine because the calcium film over the surface ‘shields’ the staining from your pool brush.
These can sometimes look like swirl marks or weird patterns 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. For example, our clients will say that their pool looked great when it was first filed, but later on, they can now see swirl marks, ridges or trowel marks that have appeared a short time later.
For more in-depth scientific information about calcium formation click here.