WRONG CHOICE! @Go go n chill
The pH of the run off is the pH of the run off - period. Soil self pH's and when you feed/water. The pH will drop around a whole point.
As the soil dries back out. The pH will rise back to the "resting place".......This provides a natural swing in pH that helps deliver the nutrients at the proper availability, as some nutrients are better available at differing pH values - between 5.5 to 6.7 basically.