OK, we have clarity on the pH meter and the Stabilizer! Thanks a LOT for that (to all the responders).
One more clarification, Kai. You say you just add minerals to the water and don't worry about separating them between mash and boil. Do you mean you treat the mash and sparge water, and not the boil? One reason I started this thread is because a fellow brewer...who appears to be well educated from a chemistry standpoint, maintains that NO mineral additions are needed to any brewing water, since the malted barley contains sufficient yeast nutrients. I gather from you previous posts you agree with that to a point, but may add calcium. So my question is, do you add that to the sparge water, the mash water, or the boil? Or does it not make any difference? (I suspect it makes no difference...).