Strips vs. Liquids

 

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. 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.

 

Industry and water quality experts report that test strips are comparable in

accuracy to liquid kits. In fact, many believe they actually deliver greater

accuracy than liquid kits because they require less technique. Many local

and state health departments now recognize AquaChek test strips as an

approved testing method. This means that professional pool and spa

service technicians as well as other industry experts trust the accuracy of

AquaChek pool and spa test strips. Today there are reliable test strips

available to test a wide variety of pool conditions, including cyanuric acid

and total dissolved solids as well as free chlorine, pH and total alkalinity.

No matter what type of test kit you decide to use, be sure to follow the

manufacturer’s recommendations to get the best results.