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How to order
Call us on
01752 698 364
Call us on
01752 698 364
There are two basic types of testing method used by most consumers: test strips and liquid kits.
Liquid kits require that you put a sample of water into a plastic comparator and then carefully add drops of
chemical reagent, watching for a change in the color of the sample. Liquid kits with the reagent OTO were
once widely used to measure chlorine, but they have fallen out of favor in recent years. OTO measures only
total chlorine, not free chlorine, which is the form of chlorine most effective in sanitizing your pool.
In addition, we now know that the chemical reagent in the OTO-type kit can cause cancer.
Kits using the liquid reagent known as DPD do measure free chlorine. However, if you test for free chlorine
using a DPD #1 liquid test kit, be aware that high levels of combined chlorine, or chloramines, can cause
false-positive results when testing free chlorine. Substances such as monopersulfate
(used for shock-treating pools) can also affect the results of the DPD test by causing a false positive reading.
Moreover, the DPD test requires careful technique and several steps to get the best results.
Test strips, the easiest method for pool and spa water testing, are fast and simple to use because they
eliminate the need to measure samples and count drops. Typically, you simply dip a strip in the water for one
second and then remove it. You then compare the color on the strip to the color chart on the label.
No matter what type of test kit you decide to use, be sure to follow the manufacturer’s recommendations
to get the best results.
Liquid kits require that you put a sample of water into a plastic comparator and then carefully add drops of
chemical reagent, watching for a change in the color of the sample. Liquid kits with the reagent OTO were
once widely used to measure chlorine, but they have fallen out of favor in recent years. OTO measures only
total chlorine, not free chlorine, which is the form of chlorine most effective in sanitizing your pool.
In addition, we now know that the chemical reagent in the OTO-
Kits using the liquid reagent known as DPD do measure free chlorine. However, if you test for free chlorine
false-
Test strips, the easiest method for pool and spa water testing, are fast and simple to use because they
eliminate the need to measure samples and count drops. Typically, you simply dip a strip in the water for one
second and then remove it. You then compare the color on the strip to the color chart on the label.
No matter what type of test kit you decide to use, be sure to follow the manufacturer’s recommendations
to get the best results.
:
What testing method should you use?
You don’t have to be a chemist to keep your pool sparkling clean. To keep things simple,
use a testing method that you find fast, easy and convenient. That way you’ll be more
likely to stick to your testing regimen.
use a testing method that you find fast, easy and convenient. That way you’ll be more
likely to stick to your testing regimen.
To keep your spa at its best, test the water before each use. (Two bathers in a 400-gallon spa
are the equivalent of 150 swimmers in a 20,000-gallon pool!) Test your pool a minimum of twice a
week. It’s also a good idea to write down your results each time you test.
week. It’s also a good idea to write down your results each time you test.
WATER TESTING: Myth and Reality