Does Pool Plaster Change Color As Curing?


Whether you have freshly plastered your pool and are satisfied with its color or are disappointed with the appearance, you want to know if it will remain the same. In one case, you’re hoping it stays the same, and in the other, you’re praying it changes. So what is it going to be?

White plaster doesn’t change color, but colored plaster can change its shade over time. If your pool has a white plaster backdrop, your pool will appear turquoise as long as it doesn’t get dirty in the first 30 days. If your pool has colored plaster, then it will fade with chlorine exposure.

This article aims to teach pool owners with white as well as ones with colored plaster how they can get and maintain the pool appearance they desire. Among other things, you’ll learn what you should avoid and what you must do to keep your pool plaster in shape during the time when its appearance is vulnerable. But first, let’s see if your pool plaster is at risk in the first place.

Does Pool Plaster Darken?

Pool plaster doesn’t darken when curing, but it changes its appearance as it cures. The darkening of pool plaster is rarely tied to the natural curing process. It is often a result of staining and discoloration due to poor water hygiene.

The possible reasons behind pool plaster getting darker are:

  • The sunshade is covering the pool – While the natural turquoise blue swimming pool color comes from a white plaster backdrop, the share becomes darker when there is an overhead shade. 
  • People are using the pool too early – The most common reason for pool plaster discoloration is that people are swimming in it too early. No one should swim in the pool right after it is plastered. The pool plaster has to cure for 10 days, at a minimum. Sometimes the plaster can get affected by water hygiene even after 20 days. 30 days of underwater curing is the sweet spot.
  • The water isn’t filtered well – Dirty water has the same effect on pool color as people swimming in the water. Ultimately, early swimmers make water dirty, which in turn stains the plaster. The same thing can happen without swimmers if you don’t clean the pool regularly.
  • The plaster isn’t getting brushed often – Aside from cleaning the pool, you need to brush the plaster so plaster dust gets removed. The dust can make plaster remain uncured for a longer period, which can lead to staining down the road.

Does Colored Pool Plaster Fade?

Colored pool plaster fades if you’re not careful about pool water chemistry. Calcium scaling on the colored plaster can make the color look lighter than it is because calcium deposits are white. You can acid wash the plaster to help it reclaim its original color.

This might make pool plaster fading seem reversible. In reality, pool plaster fading is easier to prevent and can be very difficult to reverse. The moment pool plaster loses its pigment or is buried in deposits to the point where removing them will remove the plaster, the damage cannot be reversed.

Here is how you can keep your pool plaster from fading:

  • Use hydrogen peroxide or Bromine as your main water sanitizer. 
  • Use a pool cover to keep the plaster out of harsh sunlight.
  • Test and maintain your pool pH using appropriate pool chemicals.

Does High Chlorine Damage Pool Plaster?

As mentioned earlier, Bromine is the sanitizing shock of choice for colored pool plaster. Chlorine can make colored pool plaster much lighter over time. This might make you wonder whether chlorine damages pool plaster.

In The Swim Chlorine-Free Pool Shock-Oxidizer has lower bleaching capabilities than chlorine shock. It can be used for shocking your pool or for brominating it to minimize infestation. It can work for most pools but fails at killing algae. But since algae rarely occupy circulating water, you don’t have to worry about this. 

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Why Do You Have to Brush Pool Plaster?

You have to brush pool plaster to get rid of dust that can prevent the plaster from curing on time. Uncured plaster can throw pool chemistry off balance. You also need to brush pool plaster to get rid of excess plaster.

Since pool plaster is applied by hand, it is uneven. Most of this is evened out by water circulation. But the sticky bits are evened out with gentle brushing. The trick is to avoid brushing too much or too little.

If you brush 3 times a week, you might get rid of too much plaster. If you brush it less, the excess bits might harden. The best frequency for pool plaster brushing is 2 times a week with a 3-day and a 2-day break spacing out the brushing sessions.

This is not to be confused with pool brushing, which is an alternative name for skimming. Brushing the water surface to get rid of the dirt and debris is an entirely different task and must happen daily, if not twice the day. Since the skimming brush doesn’t come in contact with the plaster, the high frequency doesn’t impact it.

How Do I Brighten Pool Plaster?

You can brighten pool plaster with an acid washing treatment. This helps get rid of calcium deposits or algae blooms. If your pool plaster is bleached by chlorine exposure, it is harder to make its color pop. You can get your pool replastered if the discoloration is irreversible.

Final Thoughts

Pool plaster changes its uniformity and appearance as it cures but doesn’t necessarily change color. However, if the pool water gets dirty or incurs a chemical imbalance, the plaster color can change for the worse. To avoid unnatural color changes, you should avoid swimming in the pool for 30 days, clean the pool regularly, and brush the plaster twice a week. Above all, you need to maintain the pool’s pH balance.

Jed Arnold

Jed spent every year from the ages of 15 - 22 as a Lifeguard (Red Cross) and ages of 17 - 22 as a Certified Pool Operator (CPO). Between working for over a dozen facilities and owning a pool, he carries over a decade of pool experience.

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