Pool Alkalinity Calculator: What to Add & How Much

Written by Michael Dean

calculating pool alkalinity

Trying to get your swimming pool alkalinity levels dialed in? No worries, I got your back. In order to find out how to raise or lower your pool’s total alkalinity, there are a few simple steps you need to take:

Total Alkalinity Basics

Total alkalinity is the measure of your pool’s sensitivity to pH change. Alkaline substances help keep your pH levels steady! If your alkaline levels are too low, it can cause pH bounce, which introduces a bunch of problems with your water chemistry like staining, ineffective chlorine, and a number of other problems. If it’s too high, it can be tough to get your pH levels to change much and also result in cloudy pool water, lower chlorine effectiveness, and lower defenses against algae and other bacteria. The ideal total alkalinity level is 80-120 ppm (parts per million).

First, Test Your Water Chemistry

Before you go add a bunch of chemicals to your pool water, you need to test your water to get accurate measurements of your current alkalinity level. Read my guide on testing your pool water with a testing kit to learn how to do it effectively.

Once you have your reading, you’ll know whether your alkalinity level is too high (above 120 ppm) or too low (below 80 ppm). To raise your alkalinity levels, you’ll add sodium bicarbonate (baking soda) to your pool water. To lower it, you’ll use muriatic acid or sodium bisulfate. I know what you’re thinking…baking soda? Yep, there are also other household products you can use to clean your pool.

Calculate Pool Volume

In order to know how much of either substance to dissolve in your pool, you need to first calculate your pool’s total water volume. Use my calculator below to figure it out.

Got the total volume? Let’s move on to the next step.

Calculate What Chemicals (And How Much) To Add

As I mentioned above, you either add baking soda or muriatic acid to raise or lower your pool’s total alkalinity level. Enter your total pool volume and total alkalinity reading (from your test) below to find out what and how much to add. I’ve already pre-filled the desired total alkalinity level to 100 ppm, but if you’re shooting for a lower or higher number inside the ideal range (80-120 ppm), feel free to adjust it. If your total alkalinity levels are too high, use the instructions that come with the muriatic acid you purchase to figure out how much to add, since concentration differs by brand.

All done! Need more help adding the right chemicals? Read my pool chemistry guides below to coach yourself up and let me know if you have any questions.

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