How long can you wait after getting sample before testing?

another one

Well-known member
Jul 1, 2010
49
Seattle area, WA
I tried searching for this answer, but "wait" gets lots of hits.

So my pool water is cold - 63 degrees, and I want to let it warm up for about 4 to 8 hours so I can test CYA. So can I just wait and test everything or do I have to test pH, FC, etc. now and CYA later?

Also, can you wait days before testing - like mail a sample to someone and have them do a test?

Thanks as always.
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,082
San Rafael, CA USA
To speed up the rate at which it forms the cloudy precipitate so that measuring after 30 seconds of mixing gives you a reasonably accurate result.
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
20,941
San Dimas, CA (LA County)
I don't think CYA will be affected by waiting, it's there or it isn't. pH will change with time. Try it yourself: take the reading as soon as you draw the sample. Then set the color block aside while you do the rest. See if it didn't move a little. Shake it up good, it will definately change. But I digress. Chlorine will dissipate with heat, sunlight, and air. So it should also be done fast. CYA endures. Oh, how I wish it would disappear on its own......
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,880
Silver Spring, MD
FC, CC, and PH can all change fairly quickly if you leave the sample sitting. TA, CH, CYA, Salt, Borate all stay more or less the same when the sample is left sitting.
 

another one

Well-known member
Jul 1, 2010
49
Seattle area, WA
Thanks for all the info. I tested with fresh water and did the hot water bath to get it above 70 degrees. New pool heater showed up today, vent pipe is coming on Tuesday. So hopefully, we'll have a warm pool next week.