Frequent water testing is the key to a clear, healthy pool.
Frequent water testing is the key to a clear, healthy pool. In this article we will be reviewing and
comparing different pool water testing methods. A well balanced pool must maintain its chemicals
within the ideal range:
Free and Total Chlorine 1- 4 ppm
Combined Chlorine 0-0.2 ppm
Alkalinity 80-120 ppm
Calcium Hardness 200-300 ppm
Cyanuric Acid 30-100 ppm
Salt 3600-3800 ppm
Phosphates 0-250 ppm
The different methods used to test pool water include test strips, DPD-drop reagents, DPD-FAS titration,
Test strips are a quick, easy, and inexpensive method of water testing. Water testing strips like
AquaChek and Taylor have long been the go-to testing method for pool and spa owners. They can test a
wide range of chemicals and with a simple dip into a collected sample, you’ll have a good picture of the
condition of the water with no technical know-how required. Though there are many pros of using test
strips, it is important to know that they can expire, become contaminated if not handled properly, and
are not as accurate as taking a sample to the local pool store.
Basic drop-test kits generally include sample vials, a color chart, directions, and reagents for free and
total chlorine, pH, hardness, and alkalinity. While more accurate than test strips, drop kits do tend to be
more expensive and they may not be reliable with chlorine levels past 5 ppm. Another method of testing
chlorine is by using titration. This method is more reliable; however, it has its drawbacks as well.
Titration tests take around 15 to 30 min and have a higher chance of user error than other methods.
Spectrophotometry is used in devices called photometers that do the color comparing electronically,
eliminating most of the chance for human error. This form of testing is the most reliable method and the
closest option to lab testing. While it is cost prohibitive to own these for residential pool owners, you
can visit your local pool store to obtain a test using this method. For example, we at Hawaiian Pools,
offer free water tests using the Waterlink spin lab. This method only takes about 60 seconds and
virtually eliminates human error. Using Waterlink we are also able to keep a record of all of our
customer’s past tests. While test strips and drop kits are reliable enough to give you an idea of your pool
chemistry, it is recommended that you bring your water sample to be professionally tested weekly. Not only would your water be accurately tested by a photometer, but we are also able to answer any questions you may have as well as walk you through the process of maintaining your pool.