The water's going to make no significant difference.
Originally Posted by georg16nik
The pH 11.8 of Calbe RO9/APH09 is not approximate, the way older R09 is made is to balance the developer so that there is no free hydroxide, at that point there is a very slight precipitation of p-Aminophenol free base crystals which is normal for this developer. That's been the case for over 100 years and only the later Agfa Gevaert version of Rodinal now sold as Adonal etc changed this.
The difference in pH 11.8 of Calbe R09/APH09 and Rodinal/Adonal etc's pH 14 is large but is purely because the first relies on more developing agent at a lower pH with no free Hydroxide and the second on less developing agent and a sgnificantly higher pH due to an excess of Hydroxide.