If you own a pool, learning to test the water is imperative. How much pool water is needed for testing? The honest answer is that it’s not a lot – maybe 500 millilitres to one litre for each test. However, what’s more important is how often you test it. Many public pools are required to test their water every hour. While you won’t need to do it that often, at the very least, you should be testing your pool water once to a few times a week. If it’s getting a lot of use or you’re getting a lot of rain, you should consider testing the water every day. In this article, we’ll go over everything you need to know about testing your inground pool water.
The Water Sample
The best time to take a water sample is first thing in the morning before the heat of the day has a chance to burn off the chlorine. Make sure the container you’re using is clean. If you’re getting the sample tested at a pool retailer, you’ll need a one-litre container with a cap. To retrieve the sample, stay clear of the pool skimmer or any jets, dip the container into the water face down to about elbow depth and turn it over before bringing it to the surface.
If you’re using a test strip kit, dip your test strip into the water sample and let it sit for 15 to 20 seconds to allow the colours to change. Don’t leave the strips in the water much longer than that or you’ll possibly get an inaccurate reading. Compare the colours of the test strip with those on the test strip package to see if your water needs adjusting.
If you’re using a pool water test kit, you’ll need to add chemicals to your water sample to check the various levels. Follow the directions on the package and add the correct number of drops of each chemical into the water sample and give it shake. The resulting colour of the water will indicate any adjustments that are necessary.
Typically, you’ll be regularly testing your pool water for pH, chlorine levels and total alkalinity. Less frequently you’ll need to test for calcium hardness and total dissolved solids. You’ll want your pH levels between 7.2 and 7.8 whereas your chlorine levels should be between 1.0 and 3.0 ppm. Total alkalinity should be between 120 and 150 ppm while calcium hardness should be between 175 and 200 ppm and the total dissolved solids should be less than 2500 ppm.
To change your pH levels, you’ll need to add an acid to lower it or an alkali to raise it. If your chlorine levels are off, you should check your feeders and make sure they’re working properly. If there’s too much chlorine, turn off any feeders and add fresh water to get back to appropriate levels. Balancing total alkalinity may take a couple of days or more to allow the added acids or alkalis enough time to fully circulate throughout the water.
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