Chow_13answered grow question 2 years ago I would recommend sticking to PH down. Its usually a mixture of different acid's which will keep your plant water more stable. Not sure where your getting your PH down. I paid for a 1L bottle at my local hydro shop and adjust my tap water( 8.2 ) with it. So far it is half done and all of my diaries are from that bottle.
Another option is to filter your water. The ph reflects whats in the water. getting a Zero water filter will get you water with 0 PPM which is esentially RO/Distilled water.
https://www.amazon.ca/ZeroWater-Ready-Pour-Dispenser-Filter-Pitcher/dp/B083KY2FZB/ref=asc_df_B083KY2FZB/?tag=googleshopc0c-20&linkCode=df0&hvadid=335507524772&hvpos=&hvnetw=g&hvrand=3257487684058240445&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9001069&hvtargid=pla-894400635794&psc=1
When you have 0ppm in your water you will need to use cal-mag, But you will need dramatically less PH adjusters to change the PH. I used it for a "Flush" at the end of one grow and went from using 2ml PH down to a few drops.
Happy Growing