Some soils, wood, additives in your tap water affect the PH and make the CO2 addition via a PH controller troublesome.
It can be used, I used it in the past but you need a backup like a drop checker to know that you are really adding the "right" amount.
Fiddling with it the first months is necessary before you get the hang of it.
Tom and Viktor might help you more, I gave up on using pressurized CO2 for now.
Mike