I repotted my plant with a cactus mix a week ago but it continues to yellow (and eventually brown)  leaves and drop them it is about a 6 foot tree so quite large and at least the bottom 2 1/2 feet of leaves have dropped. I used the root  treatment last week, as well as changed soil and trimmed damaged roots-  but still see the leaves dropping. I have not watered much lately as I know now this is an over watering issue. How long until I start seeing improvement??

also, I have a 3 way monitor (ph, sun and moisture) what should the levels be?

thank you!!!