How long do I wait after adding shock to get an accurate pH reading?

[kymom73]

Just opened pool yesterday and it was green after a hot week last week. Added 4 gallons of shock this morning and just noticed on this site that I should have tested pH first. What should I do next? I know I need more shock to kill algae but want to make sure the pH is good. Should I just wait for the chlorine to go down to normal level and test pH then proceed with more shock?

 

[Casey]

Let the SLAM level drift down to under 10ppm and then check pH. Adjust with MA if necessary to get to 7.2. Once you are there, you can SLAM again.

 

[elwood58]

Let the SLAM level drift down to under 10ppm and then check pH. Adjust with MA if necessary to get to 7.2. Once you are there, you can SLAM again.

+1. FCL over 10 ppm makes the pH test useless.