What is Total Alkalinity and How Do I Manage It?

Written by: Zach Riggs



Time to read 4 min

When it comes to pool and spa products and pool care, pool professionals throw around a lot of words like pH and total alkalinity. These terms can be confusing and overwhelming if you aren’t familiar with them. We are going to take the mystery out of these terms.

Let’s tackle total alkalinity, what it is, and how to manage it.

What is Total Alkalinity?

When we talk about total alkalinity, we’re looking at how capable your pool water is at resisting changes in pH levels.

The purpose of measuring total alkalinity is to help you control the pH level in your swimming pool. Total alkalinity is a buffer in your pool water.

For example, if something enters your pool that might make your pH levels rise or fall, total alkalinity neutralizes materials that document your collection and stay balanced. Then, your pH can better remain in the 7.2-7.8 range.

It’s important to note, though, that the total alkalinity of your pool water does not set your pH. It only works to keep the pH in the proper range.

What is the Best Range for Total Alkalinity?

Like many measurements in your pool, we measure total alkalinity in parts per million (ppm). You want to keep your pool between 80 and 120 ppm.

If your total alkalinity drops below 80 ppm, your water can become hostile, swinging your pH levels around and up and down. Conversely, if total alkalinity rises above 120 ppm, you will have high pH levels and cloudy water.

You often want to test your pool water with a test measuring total alkalinity.

Low, High, and Just Right Alkalinity

Total alkalinity comes in three states: low, high, and just right.

We mentioned that with low alkalinity, your pH levels swing back and forth between too high and too low. The result? Your pool’s pH levels are unbalanced, and you have issues. Swimmers are complaining of itchy skin and irritated eyes. You may also end up with the following:

  • Chlorine inefficiency
  • Staining on pool walls
  • Scale
  • Metal corrosion on surfaces such as filters, screws, and pipes
  • Pitting, cracking, and etching of pool walls and surfaces
  • Less effective pool sanitizers, so you need to add extra
  • Bouncing of pH levels

If your alkalinity is too high, your pH levels will usually be too high, too. If your pool is cloudy, this is a clear indication your alkalinity levels are too high. You may also end up with the following:

  • Reduced pool circulation
  • Clogged filters and pipes
  • Higher water pressure may result in cracks in your pool pump
  • pH lock where your water is resistant to pH level changes
  • Rough surface areas
  • Water scaling on pool equipment and surfaces

The best way to keep your pool alkalinity at that just-right level is to maintain your collection on an ongoing basis properly. Pay attention to water chemistry and test your water often (twice to thrice a week during the pool season).

You also want to ensure and test your pool’s alkalinity level at least twice a week.

How Do You Manage Total Alkalinity?

If your alkalinity is low, you will employ acid. You can use either liquid or dry acid over several days. This is better than making quick, significant adjustments. For example, if you add too much acid, you’ll drastically lower your pH level, and then you may end up with corroded pool surfaces and equipment, costing you a lot of money to repair or replace.

Most people use muriatic acid or sodium bisulfate to lower the total alkalinity. After you’ve added an alkalinity decreaser, be sure to check your pH level, as it may have dropped, too.

Low alkalinity levels are the most damaging to your pool, but high alkalinity levels can also cause issues. The most common problem you have with high alkalinity levels is cloudy water.

If you need to raise your alkalinity, it’s time to head to one of our favorite pool chemicals. You’ll use an alkalinity increaser, such as BioGuard Balance Pak 100. You’ll add this according to the directions on the bag over a few hours while circulating your pool water.

After raising or lowering your total alkalinity, you want to test your water again and ensure your pool is balanced.

What Happens When Both pH and Total Alkalinity Are Off?

If your pH is low and your total alkalinity is high, you want to raise your pH first to the normal range of 7.2-7.8.

After your pH is restored, then you can lower the total alkalinity.

Now, if your total alkalinity is low and your pH is high, you want to raise your total alkalinity and then reduce your pH levels.

Finally, only add acid to your pool water if your pH is less than 7. This is also true even if your total alkalinity is high. Wait for your pH to rise first. If it doesn't head up independently, you may need to add an increase.

Final Thoughts on Your Pool’s Total Alkalinity

Maintaining your total alkalinity and the pH in your swimming pool is vital. If you don’t, your pool won’t be adequately sanitized and could become corrosive. Your total alkalinity tells you how protected your water is against sudden pH changes.

These two things go hand and hand as total alkalinity stabilizes your pH levels. By keeping your levels in check, you have an excellent balance that keeps your pool healthy and clean. You need the best pool and spa products to measure and manage your pool’s total alkalinity and pH levels; we’ve got them!

Whether you have a swimming pool, a hot tub, or both, you've come to the right place if you're looking for quality pool and hot tub chemicals shipped to your door. At Pool Goods, we are here for you to help you enjoy every day in your swimming pool with the best pool and spa products on the market shipped right to you!