Keeping water PH steady when doing irrigation

I am considering going to a drop irrigation system. I noticed when I hand water and left the water sitting for a day or 2 trying to prepare for the next watering, I would notice that the ph would fluctuate. As to which direction, I don’t remember.
If I went to an irrigation system, how do you go about managing the ph and getting that accurate?
I would be doing it for a soil grow.
Also, if this is the wrong section, let me know and I can post in the best fit selection for this type of question.
Welllp... for people who understand this, please shed some knowledge on me

They make dosing pump setups that monitor pH and correct by titrating in a pH buffer. Make sure you have circulation in the tank to mix things.

https://www.amazon.com/Bluelab-CONTPH-Controller-Monitoring-Solution/dp/B00O9CBYZ0/ref=asc_df_B00O9CBYZ0/?tag=hyprod-20&linkCode=df0&hvadid=198107824285&hvpos=1o3&hvnetw=g&hvrand=5773601176651345079&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9029045&hvtargid=pla-392460311184&psc=1

You also have to keep an eye on it as when the pH probe goes bad it often runs away and just keeps adding.

Avoid the Milwaukee ones, they are garbage.