Pool pH Guide: How to Raise and Lower pH in Your Pool

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Pool pH Guide: How to Raise and Lower pH in Your Pool

Nothing beats the relaxation you get from swimming on a hot day. Not only does taking a swim relieve stress, but you add that oomph to those summer BBQs you host, too. 

However, owning a swimming pool comes with responsibilities, such as maintaining the right pH levels – a measure of the acidity or alkalinity of the water. A pH of between 7.2 and 7.8 creates optimal swimming conditions.  

In this guide, we detail why pool pH maintenance is important and how to raise or lower pH levels in your pool so you are within that sweet spot.

Why Maintain Proper Pool pH?

If your pool water is too acidic or alkaline, it may cause undesirable chemical reactions to pool equipment and yourself. Acidic pool water may corrode metal equipment, etch surfaces, and cause eye and skin irritation. Conversely, when the water is too alkaline, it may cloud the water and cause scale build-up on the pool surface and equipment. 

Worse still, unbalanced pH levels lower the efficacy of your pool’s sanitizer. If the water is too alkaline, chlorine won’t kill pathogens. When the water is too acidic, the chlorine dissipates too quickly to be effective.  

Maintaining proper chemical balance in your pool is a continuous chore because the water’s chemical balance shifts constantly. Introducing any new element – body oil, pool chemicals, water, leaves, and debris – affects the pH level of your pool water. You’ll need to continually roll back this chemical makeup shift in the water. 

Luckily, restoring the pH balance in your pool is as simple as adding the correct amount of acid or alkali. You’ll need to add an acid when the pH exceeds the optimal level and an alkali when the pH drops below the optimal swimming conditions. 

How to Lower pH in Pool Water 

If your pool’s pH is too high, above 7.8, add an acid or pH decreaser to lower it. The most common pH decreasers are muriatic acid, sodium bisulfate, and sulfuric acid. Muriatic acid is preferable because it doesn’t add sulfates to your pool water. Sulfates lead to issues like corrosion, concrete damage, and saltwater generator degradation.

Test the Water 

Before adjusting the pool water, use a pH testing kit or strips to measure its current pH. The results will help you determine whether to raise or lower the pH level. Besides pH, pool testing kits also test other parameters such as water hardness, bromine and chlorine levels, free pH, and cyanuric acid. 

Calculate the Pool’s Water Volume 

You’ll need to calculate your pool’s water volume in gallons to figure out how much acid you need:

  • Rectangular pools: length x width x depth x 75
  • Oval and round pools: diameter x diameter x depth x 5.9

Measure Out the Acid

Read the directions on the container to determine how much acid to add to the pool water. You may use an online pool chemistry calculator or manually calculate the acid dosage. 

Here are some general measurements for a swimming pool with 10,000 gallons

  • 10 ounces of 15% muriatic acid lowers pool pH by 0.1%
  • Five ounces of 31% muriatic acid lowers pool pH by 0.1%

When handling acids, wear chemical-resistant gloves, safety goggles, pants, long sleeves, and a face mask to protect your skin and eyes. Never work with acids on a windy day, as the wind may blow the fumes back to you, increasing the likelihood of inhaling corrosive air or experiencing skin or eye contact. 

Pour the Acid Mixture into the Pool 

Dissolve the dry acid in a 5-gallon bucket before pouring it into the pool. Get the pump running and pour the solution around the pool edges. Leave it to settle for 30 minutes and retest the water before adding more. 

How to Raise pH in Your Pool Water

If the water in your pool is too acidic, with a pH lower than 7.2, you’ll need to add an alkali or a pH increaser to raise the pH. Adding sodium carbonate (soda ash) or sodium bicarbonate (baking soda) is the easiest way to raise the pH levels. 

Measure Out the Alkali

After testing your pool water and calculating the water volume as explained above, you’ll need to measure the exact amount of soda ash and baking soda to raise your pool’s pH to the correct level. Soda ash and baking soda are often sold in 15-pound buckets. Here’s a simple measurement unit:

  • Six ounces of soda ash raise the pH level in 10,000 gallons of water by 0.2 points. 

To determine the amount of soda ash you need, divide the pool volume by 10,000 and multiply the results by 6. For instance, if your pH level is 7.0, and your pool holds 30,000 gallons, you’ll need to raise it by 0.2 to at least 7.2. 

In this case, you’ll need 18 ounces of soda ash (30,000/10,000) x 6 = 18. You may double the amount to raise the pH by 0.4 to 7.4. 

Add the Alkali Solution to the Pool

Mix the correct amount of soda ash with 5 gallons of water. With the pump running, carefully pour the alkali mixture around the pool’s edges. Leave the mixture to circulate for an hour, then retest the water. Repeat the process if the pH levels aren’t at the correct level. 

Note that the pool water may turn cloudy after adding soda ash but usually clears after a few hours. 

Pool pH Maintenance and Expert Care

You’ll need to skim debris and leaves from your pool and test chemical balance weekly for proper pool pH maintenance. Additionally, you’ll need to monitor water hardness, total alkalinity, and total dissolved solids to maintain proper chemical balance in your pool. 

Having trouble keeping your pool in tip-top shape? Our team of highly trained technicians at Hot Springs Pools & Spas can help. We have served property owners in Greenville, South Carolina, and Asheville, North Carolina, for over 30 years.

Schedule a pool service today to get started!

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