This is an interesting case. Can you tell me what is your GH and KH, in ppm please (tap and tanks).

I can't remember last time I have checked the pH... but I do test for GH and KH occasionally, which is in my opinion the important part of buffering the systems pH and binding acids.

My tap is also way too soft, and for that reason I added a fair amount of CaCO3 (couldn't find any Dolomite) into my soils (2 new tank), so they don't get too acidic over time.
Beside that I will also dose the GH-Booster every week.

Regards, Dusko