are there calculations to adjust for testing at different times of the day?

[Jcon82]

I do my best to test at the same time of day, between 5 and 6pm. But sometimes I cant be home to do my weekly or bi-weekly testing. Are there any rough calculations that I can use to approximate if I tested 3-4 hours early or late? I've seen a considerable difference in alkalinity just when testing an hour early or late that make me disregard the results. I'm mainly testing alk calcium and N03 right now.

My partner would greatly appreciate me not getting grumpy at a labor day cookout when I miss my testing window!

 

[Randy Holmes-Farley]

No, I don’t think that’s feasible without a great deal of testing on a given system to see how whatever you are measuring changes in that system.

That said, pH and ORP (and a few we rarely measure, such as O2) are the primary ones where there are natural daily up and down changes. Must other things are a slow decline between additions of various sorts.