Zandor,
What chems are you using for the pH, I am using Nitrogen and phosphorus acids and bases, on low concentrations, I use about 3-6ml at a time, for a 50L res, to control pH, i looked at some pH up and down, but it does not say the chem, or chems used to do so.
So If I read correctly you find that the pH up or down is better than co2. At least for your setup. And since you used co2 before, do you find it disappated into the air fast.

And also I am not automated yet, so i have noticed that i need to adjust my pH every hour or so. Is this common.

If I don't make sense please ask me to clarify.