Best time to Test?

Hi all,

I was wanting to know, when is the best time to test water. In relation to when pump was last used. I run my pump on average 4-6 hrs a day, sometimes longer. Is it best to test before, during, or after pump has been on.

Yesterday, pump did not get turned on. Today before I turned pump on I tested water. Water is crystal clear but I got some not so good test results and was wondering if maybe the test results could be flawed, because I was testing water that had been stagnant for a day. I have a 21K gallon, 16x32, IG, Vinyl pool. Sand filter with Haywad 1hp pump.



Test results were:

FC - .23 ppm
TC - .98 ppm
CC - .75 ppm
PH - 8.1
AK - 207 ppm
CYA- 61 ppm

thanks

Best to run the pump for a bit before testing and testing in the evening when the sun is off the pool is the preferred time. (4-6 hours per day may not be enough run time for your pool, btw.)

You stated above that you tested your water. How did you get those test results with decimals to two places? And a CYA reading of 61? It is hard enough to distinguish between 50 and 60 much less to 61. Those look like pool store readings which typically aren't very accurate. Just wondering.

Your chlorine is too low, your pH and alk are too high. Do you know how to adjust those?