How to Check Pool Chemicals

Checking pool chemicals is an essential part of keeping your pool clean and safe. If you're not sure how to measure pool chemicals or how pool chemicals work, then this guide will help you to become a better-informed pool owner.

How Often Should Pool Chemicals Be Checked?

Knowing when to check pool chemicals is the first step in maintaining your pool. The best time is in the morning, as levels of pool chemicals can be affected by sunlight during the day.

How often should pool chemicals be tested? Most experts recommend checking every day, but if you can't manage that, commit to checking chlorine and pH at least twice a week.

How to Test Pool Chemicals

Take a sample of pool water from about 12-18 inches below the surface. If you're using test strips to check your pool chemicals, dip the strip into the pool water and wait for 10-20 seconds for the strip to change color. Compare the color of the strip to the chart that comes with the strips to get an accurate reading.

If you're using a test kit to take your measurements, you'll need to add the reagents included in the kit to the water, according to the kit instructions. Add the reagents slowly and wait a few seconds for them to react with chemicals in the water before you take your reading.

How to Adjust Pool Chemicals

After testing your pool water, you may need to adjust chemical levels to bring them within the following acceptable ranges:

• Chlorine: 1-2 parts per million (ppm)


• Cyanuric acid: 40-80 ppm


• pH: 7.2-7.8


• Alkalinity: 80-120 ppm


• Total dissolved solids: below 5,000 ppm


• Calcium hardness: 180-220 ppm

You can increase chlorine levels by adding chlorine tablets to your pool skimmer. Adding cyanuric acid helps to keep your chlorine levels stable, as it prevents the sun's radiation from breaking down the chlorine. Muriatic acid is a useful chemical for controlling pH and alkalinity. If your calcium hardness and total dissolved solids are too high, you may need to partially drain the pool and refill it with fresh water.

After testing your pool chemicals, you may need to take action to bring their levels into the acceptable ranges. Wait for at least 24 hours before testing your pool water again, as the chemicals you add can take up to a day to have their full effect.

Where to Add Pool Chemicals

Increase the chlorine level of your pool by adding a chlorine tablet to your skimmer basket or chemical feeder. It's best to do this at night, so the sun's rays don't break down the freshly added chlorine. Add liquid chemicals to the pool close to a return line fitting and leave the filtration system running to help the chemicals disperse through the water. When handling any pool chemicals, it's a good idea to protect your skin by wearing long pants, long sleeves and gloves. If you accidentally splash chemicals on your skin, wash with soap and water to avoid skin irritation.

When you own a swimming pool, it's important to know how to check pool chemicals and adjust the levels if necessary. Remember to test as often as you can -- at least twice a week -- to ensure that your pool chemicals stay within acceptable ranges, which can help keep your pool water safe for swimming.