Can I test yesterday’s water sample?

thefloatqueen

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Dec 24, 2018
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I filled up my sample bottle with water yesterday and it was super cold so I let it sit and forgot about it until this morning. Is the sample still good to test? I could go and get a fresh sample but the water has a tiny bit of ice on the surface in the middle so I don’t know if it’s too cold. Plus I wanted to test the CYA and I know that test is sensitive to cold water. I know this is a dumb question but I couldn’t find it in the search bar lol. Thanks in advance!!
 

mknauss

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The only test possibly effected by cold water is the CYA test. It is not likely you need to test CYA level at this time of year.
If you wish to test CYA, use the old sample for just that test.

The FC and pH can and most likely will be incorrect with a sample that has sat for an extended time. I suggest you get a fresh sample of pool water to test.
 
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thefloatqueen

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Dec 24, 2018
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The only test possibly effected by cold water is the CYA test. It is not likely you need to test CYA level at this time of year.

The FC and pH can and most likely will be incorrect with a sample that has sat for an extended time. I suggest you get get a fresh sample of pool water to test.
Thank you so much! That’s all I needed to know! Prior to closing, my CYA was 50.
 

thefloatqueen

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Dec 24, 2018
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Can I test FC and pH right away even though the water is around 38-40 degrees or should I wait a few hours after taking the sample bottle inside?
 

thefloatqueen

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Dec 24, 2018
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Test the FC and pH right away. The only test effected by water temperature is the CYA test.
Done! FC is 5.5 and pH is 7.2. Haven’t added any chemicals since I closed November 6th so I’m surprised. Can I test CYA when the water sample warms up a little? I haven’t tested it all winter and it’s bugging me is the only reason I ask lol
 

mknauss

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May 3, 2014
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Laughlin, NV
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I edited my original post, not sure if you saw that. You can use your old sample or let this one warm up to room temperature and then do the CYA test. You do need bright sunshine to do the CYA test properly.
 
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