Does PO4 change during the day?

[NormanB]

Title says it all.

Just wondering if I should test at about the same time of day for repeatable results.

Thanks

 

[Randy Holmes-Farley Verified Community Expert]

There's not a lot of good info on the timing of uptake of phosphate by photosynthetic organisms and release (after metabolism of foods) , but some folks do report changes during the day. I'm just not certain how many of those reports reflect random test variation and how many are actual changes.

It's certainly reasonable to test at the same time, and maybe even a few times on one day to see for yourself in your system.

 

[NormanB]

Thanks Randy!

Normally I test other parameters mid afternoon, but PO4 is tested more often and at random times that fit my schedule.