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About Test Kits

For a test kit to be trustworthy, you have to be able to easily translate the results to an effective treatment or maintenance action. That makes calculating treatment dosages easier and more accurate, so there are less wasted chemicals.


A DPD test is a swimming pool water test which measures the oxidizer level in the pool water, such as free and total chlorine, bromine, and ozone. It is the best method if you sanitize your pool with any type of Chlorine including tabs, granular or bleach. DPD is recognized by public health authorities as the best method for testing pools and spas.


This variation of the traditional DPD method allows users to measure both free and combined chlorine levels as low as 0.2 ppm (the maximum allowable level according to most health authorities as well as the Pool and Hot Tub Alliance). The high measurement is 20 ppm. By contrast, the color comparators used with the regular DPD generally allow readings as low as 0.5 and 1ppm and as high as 5 or 10 ppm.


One option for testing uses a liquid chemical OTO (orthotolidine) that causes a color change to yellow in the presence of total chlorine. Using a comparator, you would look for the color change. OTO is recommended for pools that are sanitized using Bromine. This method ONLY measures total chlorine and is not permitted to be used at regulated facilities. It does not measure free chlorine.


Speciality Kits do not measure any sanitizers but concentrate on specific elements like hardness, copper, hydrogen peroxide, etc. These kits typically use a drop test and comparator system for a visual measurement.


Digital test kits use an electronic device to provide more precise measurements of pool sanitizer levels, pH, acid, etc. These kits are ideal for pool professionals and service technicians as they provide precise measurements within seconds.