[trapae]

Can using proper water chemistry and mash pH affect length of early active fermentaion?  Reason I ask is that this current brew is the 1st time I’ve adjusted water chemistry and mash pH (as opposed to just mashing/brewing with spring water)—and I noticed that the first 3days of fermentation were more vigorous, and then the bubbling dropped off to almost nothing by day five. Normally, it is pretty vigorous but steadily bubbles for over a week then slowly drops off.  Nothing else  has changed in my recipe or bring practices.   Just wondering if it has to do with the correct water or mash pH? 

[mabrungard]

Maybe. Getting the process pH into the proper range does improve the conversion process. So its possible that it could improve the fermentability of the wort.