forgot to check PH before slamming

[thegoat54]

Opened a very dirty pool this week. Started slamming but forgot to check PH.

Does that matter? Will it affect the SLAM? Can't I just adjust PH later?

 

[Texas Splash]

We lower the pH because the higher bleach/SLAM level increases the pH. For some that can be a problem if the SLAM lasts a long time (i.e. scale). Your call depending on how bad the water is. Since the FC tends to fall quite fast in the beginning of a SLAM, now is the time to just let it fall to 10 or less long enough to verify the pH, adjust, and then crank it back up.
SLAM Process

 

[Mendy48]

Like Pat said... let your FC fall (now) to 10 or less and test your then test your pH. Try to get your pH around 7.2.