Do Pool Test Strips Go Bad? 2 Main Causes

pool owner dipping a white test strip into the water

When you first get your pool up and running, you need to test the water.  This will help you prevent algae and many other problems. Maybe you went out and got some test strips.  As you’ve undoubtedly figured out, they are really easy to use.  Throughout the season, you’ve used the strips weekly to make minor adjustments to the water chemistry and kept your pool looking good.  When next spring rolls around and you’re ready to open the pool, will the test strips still work?  Do pool test strips go bad?

Do Pool Test Strips Go Bad?

Absolutely, yes, test strips go bad.  First off, if you have test strips which you’ve stored anywhere other than in a sealed container, they aren’t any good.  Test strips are sensitive.  That’s the point. Test strips can sense delicate changes in water chemistry.  They are engineered in a laboratory to be capable of detecting minute changes.

Unfortunately, many people just assume they’ll be fine if they leave them out or put them in a drawer.  You really ought to leave them in the container they came in, opening only to pull out a strip for use with dry fingers.

Does Weather Make Pool Test Strips Go Bad?

Moisture from the air, sunlight, rain etc. will all render a test strip useless.  Assuming you keep your test strips in the container and out of the sun, you’re off to a good start.  What if you leave the container out by the pool equipment where it can bake in the sun?  You are not storing the test strips properly and will find the results given are not accurate.  You need to store your test strips in a climate controlled environment, usually around 77 degrees Fahrenheit.  Make sure to read the bottle and follow the instructions to the letter.

Do Pool Test Strips Go Bad After A Certain Date?

Next, there is a date at which the test strips are no longer considered accurate.  This is simply due to age and exposure to the inside of the bottle after manufacture.  They simply go bad.  When test strips have aged out, you need to throw them out.  There is no reason to use old or improperly stored test strips.  You will be getting irregular results which should be considered meaningless until you test with a test kit or new test strips.  

human hand and white test strip container showing the answer to do pool test strips go bad as yes with an expiration date on the bottle

Test Strip vs. Test Kit

With all this trouble, why not use a test kit instead?  That is a good question, and we always recommend using a test kit instead of using test strips.  Yes, you still need to store the reagents properly, but they are far more forgiving than test strips.  Additionally, a test kit will give you an accurate reading on your water chemistry.  There’s a reason professionals do not use test strips, and instead rely on test kits. 

The industry favorite among service professionals is the Taylor Service Complete Pool Water Test Kit K-2006C.  This test kit costs about 5-7 times as much as a high quality set of test strips like the AquaChek 7.  However, your readings with the Taylor kit will be more accurate, and you’ll have access to more testing options.   As your reagents age out, you can replace them one by one on an as needed basis.

Do Pool Test Strips Go Bad Summary

Ultimately, the answer to the question ‘do test strips go bad?’ is that yes, they do.  Be prepared to store your test strips properly, and replace them often.  Do this and you’ll be able to keep your pool in swimmable shape. If you can’t do this, buy a high quality test kit instead.