Testing Pool Water

A pool owner needs reliable testing and sampling procedure using reagents, test strips, or digital probes to perform basic maintenance tests for pH, alkalinity, calcium hardness, and of course chlorine (sanitizer). In some situations, you may also want to test for metals, stabilizers, and salt levels if you are running a saltwater pool. What is the best way to test pool water?

  • Use a reliable pool testing kit
  • Change reagents & strips every season
  • Sample pool H2O at least 18″ down at deep end
  • Sample & test in AM-before start of the day
  • Sample & test in PM-at end of the day
  • Test sample within 5-10 min. of collecting
  • Be consistent when collecting samples & testing
  • Clean comparators


Pool water testing is always done at least weekly and a Pool that is used daily should be tested 2-3 times a week especially if the pool owner is new to maintenance and how usage and temperatures fluctuate reading during the season.

Swimming Pool Water Testing


Learning to test and sample your pool water should be part of your maintenance learning curve if you are a pool owner. Depending on the size of your swimming pool should dictate how much time and money you put into testing or monitoring equipment.  Testing the chemistry of the pool water can not only keep your pool looking great but save you a ton of time and money.

Testing should be done either before the pool opens at the start of the day and is empty or after the pool is closed at the end of the day and is empty of all swimmers so that any chemical adjustments that need to be made can be made and have some time to react before the things get busy again.

Maintaining a proper chemical balance will prevent bad things from happening and keep you in the water not above it and at the Pool Supply Store. Work out scheduled maintenance time that will fit with yours and be consistent as best you can. If there are situations (and there will be that warrant more testing) like heavy storms or heavy usage then always test.


Sampling Pool Water 

  • Buy a reliable Pool Testing Kit and Reagents-(for an Inground larger pool I would go a few extra bucks)
  • Read Instructions carefully
  • Store Test Kits and  Test Strips in a cool dry area
  • Sample in the AM-before the kids go in (after the filter has been running) or
  • Sample in the PM after the kids are done for the day (before adding chemicals)
  • Sample in the deep end of the pool (approximately 18 inches down)
  • Run the Test Sample right away or within 5-10 minutes (keep out of Sun)
  • Be consistent with sampling and testing (Where and When)


How To Take A Water SampleTry not to touch any sample or test strip with your fingers. Believe it or not, your fingers can change the test results if they come in contact with the solution, caps on the comparator, reagents, or color strip which will lead to erroneous results. Pool sampling should be clean and consistent for the best results. Make sure to fill to the meniscus level on the mark on the column for liquid kits.

Shake the liquid test Reagent before adding the drops to the sample cell or comparator. Cap the chemical reagent and return it to the test kit keeping it away from UV sunlight around the pool area. 

Hold a white background at the back of the color comparator for a better contrast between eyeballing comparisons. Wait appropriate time for chemical addition to work before adding more. Know your pool turnover rate in hours and dimensions of your pool. 

When using Test Strips, take an isolated sample of the pool water in a clean container to be tested instead of trying to dip the strip into the pool itself. The strips always break down and contaminate by folding up then bleeding over the pads and touching your skin. Not very reliable


Best Pool Water Test Kit


How to Read a Pool Test Strip Color Chart | Clorox® Pool&Spa™When looking for a reliable Pool testing Kit you need one that is easy to read and can perform the standard pool test with enough reagent for the season. I always recommend liquid reagent testing because of its more exact results in the Pool Chemistry Cheat Sheet for Chlorine Pools | Zagers Pool & Spa Drop test at the very least for pH, Chlorine, and Alkalinity.

Good kits come in polyethylene carry cases that protect the chemicals and contain a number of tiny plastic bottles filled with reagents depending on the size kit, you may have two or more reagents. The bigger the pool the more elaborate your Test Kit should be.

When testing your pool’s H2O with a liquid reagent kit,  just fill the included vials or comparator with pool water samples from your chlorine or saltwater pool, and then add the liquid reagent according to the manufacturer’s instructions.

Counting the drops as you mix the reagent with your water samples, the samples will change color and give out a reading. After the test is completed rinse out the comparator. The reagents will stain the plastic and give faulty readings.

 Pool Testing Strips are the easiest and can be good if you are operating a smaller spa or above-ground pool that doesn’t demand a whole lot of testing. They can be reliable as long as they are used properly.

Digital electronics- are the convenient new generation in pool water testing and monitoring, specially built for Saltwater pools where salinity (salt) is an important measurement. They are smart instruments and some have built-in meter calibration, temperature compensation, and Salt NaCl conversion. Probes have a working life and some need re-calibration which can be a hassle.





What Causes High pH in Pools

For great information on controlling pH and other balance testing for pool water stay right here at MyWaterEarth&Sky-Water pH is a measure of the acidity of water tested and is the most routine pool water test along with chlorine residual that a pool operator will perform at……………Continue reading


JimGallloway Author/Editor





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