How to Test Pool Water How Often to Test Water? What are normal pool chemical levels? What pool test kit do you need? How to Use a Liquid Test Kit Extra Tips

How to Test Pool Water

Testing Pool Water, Pool Water Chemistry | Pool Maintenance

Testing your pool is a regular part of pool ownership. It’s essential to maintaining water that is crystal clear and algae free. It’s also important to maintain a good balance of chemicals in your pool because improper water chemistry can cause damage to your pool and equipment. Beyond that, imbalanced water can cause eye irritation and hair discoloration. Yikes. To get an accurate reading, you'll need a test kit, a test strip, or a water sample for a pool professional.

How often should you test your pool water?

Test at least once each week, more if you are using the pool heavily. You may want to test 2-3 times a week if you are new to pool maintenance until you get used to the fluctuations. It can help to pick one day a week to routinely test your water.

What are normal pool chemical levels?

The main chemicals to check in your pool are the pH, alkalinity, calcium hardness, and chlorine (sanitizer). In some situations, you may also want to test for metals and stabilizers. Here are the suggested levels to maintain a balanced pool:

Test Range
pH 7.2 - 7.6
Total Alkalinity 120 - 150ppm
Calcium Hardness 200 - 250ppm (Concrete Pools)
Calcium Hardness 175 - 225ppm (Vinyl Pools)
Free Chlorine 1 - 3ppm
Free Bromine 3 - 5ppm
Metals: Copper 0ppm
Metals: Iron 0ppm
CYA 30 – 50 ppm

What pool test kit do you need?

There are three main ways to test your pool water, each have their advantages:

Liquid test kit (Reagent Color Test Block)

The liquid test kits use a testing container and reagents, which are the liquids that come in the dropper bottles. They tend to be very accurate and test for all the major chemicals. Pool professionals tend to favor this kind of test.

Test Strips

Test strips are easy and fast to use but can be less reliable than liquid test kits since they expire. Test strips are one-use only, so they are a little more expensive than liquid in the long run.

With a Professional

If you are having trouble balancing your pool or are unsure how to treat imbalances in your chemicals, you should bring your water to a pool store. This makes it as easy as possible to get the right chemicals since a professional will handle the diagnosis and treatment for you.

How to Use a Liquid Test Kit (Reagant Color Test Block)

  1. Use the clean, empty testing container included in the kit
  2. Take the sample away from jets and skimmers
  3. Dip container upside down until elbow deep, then take the sample
  4. Add liquid reagents in droplets as suggested on the instructions provided by the kit. Usually the left side (yellow) measures chlorine and the right side (red) measures pH.
  5. Seal the container and shake. If possible, avoid covering the top with your hands since acids on the surface can affect results.

How to Use Test Strips

  1. Use a clean, empty cup
  2. Take the sample in the middle of the pool away from jets and skimmers
  3. Dip container upside down until elbow deep, then take the sample
Pool Test Strips, Testing Pool Water

How to Provide a Sample to a Pool Professional

  1. Use a clean, empty water bottle (12 oz - 16 oz)
  2. Take the sample in the middle of the pool away from jets and skimmers
  3. Dip container upside down until elbow deep, then take the sample
  4. Bring the sample into your local pool store

Extra Tips

  • Sample deep
  • Make sure pool has been running for at least 15 minutes. An hour is ideal.
  • Make sure filled to “fill” level on the column for liquid kits
  • Mix the solution with a cap if possible, acids from hands can affect results
  • Rinse in a sink, not in the pool
  • Testing strips should be stored in a cool, dry area

How to Add Chemicals Safely

  • Always read and follow the chemical’s instructions to ensure safe use of chemicals.
  • Wear appropriate protective equipment and clothing including gloves, footwear and eyewear.
  • Handle chemicals in a well-ventilated area.
  • Use separate, clean metal or plastic measuring cups for each chemical to transfer or measure chemicals. Never use wood scoops.
  • Protect chemicals from moisture and water—such as a cup of water or coffee. Even putting the wet scoop back in the pail may cause a reaction.
  • When applicable, always dilute chemicals by adding to water, never the other way around unless the container’s label instructs you to do so.
  • Do not mix different chemicals together.
  • Do not put spilled chemicals back into their containers.
  • Do not smoke when handling chemicals.
  • Do not expose to heat or flames.