Monday - Friday from 8am to 5pm
logo for ogden pools which is a custom swimming pool builder and pool maintenance company in Memphis, TN
Monday - Friday from 8am to 5pm
What Is Swimming Pool Alkalinity?

What Is Swimming Pool Alkalinity?

Aside from chlorination, the single most important aspect of maintaining a clean pool is balancing its pH. For that, you must make the pool slightly alkaline, which in turn stabilizes the pH. In the absence of alkalinity, the pool water can become acidic and irritate the swimmers’ skin. This article will explain how you can avoid spontaneous acidity and ensure swimming pool alkalinity. Let’s get started with what swimming pool alkalinity is.

Need Help Balancing Your Pool Chemicals? Check out Pool Chemicals: How to Get The Right Balance

Balancing pool chemicals is a complicated and important year-round job. Our pool chemicals guide can help you achieve the right balance for your pool.

Swimming Pool Alkalinity: The opposite of acidity?

Pool water is either acidic or alkaline, so it might seem like alkalinity is the opposite of acidity. But in reality, alkalinity is the resistance to acidity. To the extent that water is alkaline, it is not acidic. An analogy of fire and darkness best illustrates how alkalinity is inversely tied to acidity. Fire is not the opposite of darkness, but its presence gets rid of darkness as it produces light.

Alkalinity is literally the measure of the water’s ability to resist a pH change towards acidic from basic or neutral. The more alkaline the water is, the more acidic contents can be added to it without its pH dropping below 7. But if enough acid is added to the water, it overrides the free alkalis dropping the total pH alongside the alkalinity.

Because acidity in pool water can lead to skin irritation, eye irritation, and general corrosion, it is best to lean on the side of alkalinity when balancing the pool’s pH.

The Pros of Swimming Pool Alkalinity

To make your pool more alkaline, you need to add or use sodium bicarbonate. Here are the main advantages of sodium bicarbonate and its consequent alkalinity.

  • It stabilizes the water’s pH – This one aspect can get rid of many complicated problems that arise from poor pH management.
  • It reduces acidity – As a result, the water is safe to swim in and less likely to cause irritation and itching.

The Cons of Swimming Pool Alkalinity

Swimming pool alkalinity is a net positive, but not if you go overboard with it. There really is too much of a good thing with alkalinity, even when you raise it to just over 120 ppm.

Here are the drawbacks of making your swimming pool too alkaline.

  • It can lead to calcium deposits – Calcium carbonate produced as a result of excessive alkalinity can be deposited in the plumbing and across the pool lining. Scaling is the greatest drawback of making the water too alkaline.
  • It can make the pool cloudy – The calcium carbonate deposits can fragment and form a powdery suspension in the circulating water. As a result, the pool has a cloudy appearance.

How to measure the alkalinity of your pool water?

Again, pool alkalinity is good BUT within reason. To avoid making your swimming pool too alkaline, you need to add sodium bicarbonate in small increments and measure the alkalinity and the pH of the water.

To measure pool alkalinity, you must use a pool testing kit that can measure alkalinity. For a pool that doesn’t have fresh plaster, you can simply measure the pH and infer the alkalinity level. As long as the pH is no more than 7.8, the pool is alkaline within reason.

There are risks involved with measuring and balancing your pools chemicals. At Ogden Pools, we offer a variety of different options for taking care of this for you on a weekly basis. View our options here.

How to make a pool more or less alkaline?

Measuring pool alkalinity is useless if you cannot alter it according to your needs. Fortunately, you can increase and decrease your swimming pool’s alkalinity.

To make a pool more alkaline, you must add sodium bicarbonate to it. If the total chlorine content isn’t excessive, you can even add chlorine to raise the pH (and the alkalinity). To decrease a pool’s alkalinity, you must add muriatic acid or sodium bisulfate to it. Both muriatic acid and solutions featuring sodium bicarbonate are acidic, which reduces the alkalinity and the pH of the pool.

Get Your Water Tested For Free By Ogden Pools

We always say it’s best – with safety in mind – to let professionals help you test your water and maintain your pools chemistry. Give us a call. We’ll come out and test your water for free and provide you with options for having us provide the weekly maintenance and chemical balancing for your swimming pool.

Final Thoughts

Swimming pool alkalinity is a measure of the pool water’s ability to resist becoming acidic. Water left to stagnate can gradually become acidic, especially in a high-precipitation environment. From carbon dioxide exposure to acidic pool chemicals, many factors can bring the pool’s pH down to 6.5, which can cause skin irritation and itching. Swimming pool alkalinity stabilizes the pH of the pool and ensures that it is safe to swim in.


Popular Articles & Resources