It all is very relative and you can have equal good results in a wide range of parameters.. Hunting the ideal and change what is supplied from the tap oftenly only results in more work, frustration to keep it stable, more confusement and in worst case scenario more failure than succes.
I got about the same values in my tap water as yours. Didn't measure it for a long time now but last i remember it maybe differed 1 or 2 degrees and with a average pH > 8 after water is depleted and in natural equilibrium. Far from the theoretical ideals for many maybe. Even in my low tech it took some time and patience but mean while my fissidens is growing like a champion.
I guess that's the price people pay for watching high energy tanks expecting high speed results.. And if this stays behind go on a wild goose chase to find a culprit before the lights go out..