How Do I Increase Alkalinity in My Pool?

Add baking soda (sodium bicarbonate) in small doses to raise total alkalinity levels to 80-120 ppm.

What Is Total Alkalinity and Why Does It Matter?

Total alkalinity (TA) measures the concentration of alkaline substances in your pool water, primarily bicarbonates. It acts as a buffer, stabilizing pH levels and preventing rapid fluctuations.

Ideal alkalinity range:

• 80-120 ppm (parts per million) for most pools

• 100-150 ppm for pools using saltwater chlorine generators

When alkalinity is too low, you may notice:

• Rapid pH fluctuations (pH bounce)

• Corrosion of pool surfaces, ladders, and equipment

• Skin and eye irritation for swimmers

• Reduced effectiveness of chlorine and other sanitizers

How to Test Your Pool’s Alkalinity

Before adjusting alkalinity, you need to determine the current level using a reliable test kit.

Steps to test alkalinity:

1. Use a liquid test kit or test strips specifically designed for total alkalinity.

2. Collect a water sample from about 12-18 inches below the surface.

3. Follow the kit instructions to determine the TA level in ppm.

4. Compare results to the ideal range (80-120 ppm). If it’s below 80 ppm, it’s time to increase alkalinity.

How to Raise Alkalinity in Your Pool

The best way to increase alkalinity is by adding sodium bicarbonate (baking soda) or alkalinity increaser to the water. Here’s how to do it correctly:

Step 1: Determine the Required Amount

Use this guideline for adding baking soda:

• 10 ppm increase in a 10,000-gallon pool = 1.5 lbs of baking soda

• Adjust based on your pool’s volume and how much you need to raise the alkalinity.

Step 2: Add the Baking Soda or Alkalinity Increaser

1. Turn off the pool pump to allow the water to settle.

2. Pre-dissolve the baking soda in a bucket of pool water for even distribution (optional but recommended).

3. Slowly pour the solution around the perimeter of the pool.

4. Wait 6 hours, then turn the pump back on to circulate the water.

5. Let the water circulate for 12-24 hours before retesting.

Step 3: Retest and Adjust If Needed

• After 24 hours, test alkalinity again to check if it falls within the recommended range.

• If still low, repeat the process by adding smaller amounts to avoid overshooting the target.

Common Mistakes to Avoid

• Adding too much baking soda at once: Can lead to cloudy water and high alkalinity.

• Not testing pH alongside alkalinity: Alkalinity changes can impact pH balance.

• Using the wrong chemicals: Avoid using products like soda ash, which can raise pH too quickly.

• Not allowing time for circulation: Let the pool pump run long enough to distribute chemicals evenly.

Preventing Low Alkalinity in the Future

• Test water weekly to monitor alkalinity and pH levels.

• Avoid excessive rainwater dilution, which can lower alkalinity over time.

• Use quality pool chemicals to maintain stable water chemistry.

• Balance pH and chlorine properly to prevent imbalances that lower alkalinity.

By following these steps, you can keep your pool’s alkalinity at the ideal level, ensuring a comfortable swimming experience and prolonging the lifespan of your pool equipment.