How do I Lower Total Alkalinity in my Pool?

Add muriatic acid or sodium bisulfate in small doses while running the pump, and retest levels regularly.

Why is Total Alkalinity Important?

Total alkalinity (TA) is a measure of the water's ability to resist changes in pH. The ideal alkalinity range for pool water is between 80 and 120 ppm (parts per million). If your pool's total alkalinity is too high, it can lead to problems with the pH. A high alkalinity level makes it harder to adjust the pH levels, and can result in the water becoming cloudy or causing stains and scaling on pool surfaces.

Signs Your Pool's Alkalinity is Too High

Before you lower the total alkalinity in your pool, it's important to determine whether it's too high. Here are some common signs:

• Cloudy Water: High alkalinity can cause cloudy water, as it prevents the pH from being adjusted correctly.

• Scale Buildup: A high alkalinity level can cause calcium buildup on the pool walls and equipment.

• Difficulty Adjusting pH Levels: If you’re constantly adding acid or base to adjust pH, it might be due to high alkalinity.

Methods to Lower Total Alkalinity

Now that you know why it’s important to lower the total alkalinity, let’s dive into how to do it safely and effectively.

1. Add Muriatic Acid

The most common and effective way to lower total alkalinity in your pool is by using muriatic acid. Here’s how to do it:

• Test the Water: Use a pool testing kit to check the current alkalinity level. If it’s above 120 ppm, you’ll need to lower it.

• Calculate the Amount of Acid: Based on your pool size and the alkalinity level, calculate the appropriate amount of muriatic acid. Most pool stores have calculators to help with this.

• Add the Acid to the Pool: Slowly pour the muriatic acid into the pool near the return jets or deep end. Always add acid to water, never the other way around. Be sure to wear protective gloves and eyewear, as muriatic acid is corrosive.

• Allow the Water to Circulate: Let the pool pump run for at least 4-6 hours after adding the acid. This helps ensure the acid is properly distributed.

• Test Again: After a day or two, retest the water to check if the alkalinity has dropped to the desired level.

2. Use Sodium Bisulfate (Dry Acid)

Another option for lowering alkalinity is sodium bisulfate, commonly known as dry acid. This works similarly to muriatic acid but in a granular form.

• Test Your Water: Check the alkalinity level before using dry acid.

• Calculate the Right Amount: Follow the instructions on the dry acid packaging to determine how much to add based on your pool size and current alkalinity.

• Distribute the Acid: Sprinkle the dry acid evenly around the pool’s edge.

• Circulate the Water: Let the pool pump run to mix the acid thoroughly into the water.

• Retest: After a day or two, test the alkalinity to see if it’s within the desired range.

3. Dilute the Water

In some cases, if your pool’s alkalinity is extremely high, you may need to partially drain and refill your pool with fresh water to dilute the alkalinity.

• Check the Current Alkalinity: If it’s over 180 ppm, draining may be your best option.

• Drain Some Pool Water: Use a submersible pump or your pool’s drainage system to remove a portion of the water.

• Refill with Fresh Water: Add fresh water to your pool to help lower the alkalinity level.

• Retest and Balance: Once you’ve refilled the pool, test the alkalinity again and adjust as needed.

What to Avoid When Lowering Total Alkalinity

While lowering the total alkalinity is important, there are a few things you should avoid to ensure the process goes smoothly:

• Over-Correcting: Don’t add too much acid at once. Make small adjustments and test regularly to avoid drastic swings in pH and alkalinity.

• Ignoring pH Levels: After lowering alkalinity, check and adjust the pH as needed. Often, the pH will drop along with alkalinity, and it may need to be raised back to the optimal level (7.4-7.6).

• Adding Chemicals in Large Quantities: Avoid adding large amounts of any chemical in one go. It’s best to add small amounts and gradually reach the ideal alkalinity.

Maintaining Balanced Alkalinity

Once you’ve successfully lowered the total alkalinity in your pool, it’s important to maintain it. Regular testing and adjusting are key to keeping your pool’s water in perfect condition.

• Test Regularly: Test the alkalinity every few weeks to ensure it remains within the ideal range of 80-120 ppm.

• Balance pH Levels: Since alkalinity and pH are linked, make sure both are balanced. Adjusting one can affect the other, so always keep an eye on both levels.

• Clean the Pool: Regular cleaning helps prevent scale buildup, which is a common result of high alkalinity.

By following these simple steps, you can easily lower the total alkalinity in your pool and keep your water sparkling clean and balanced.