My customers got their water from either of two municipal water
supplies.
One was slightly soft and acid, the other slightly hard and alkaline.
But either was acceptable for the average community tank, assuming
regular
partial water changes were done.
For customers requiring buffering I always recommended peat or dolomite
in the filter. But some always insisted on the use of chemicals.
In most aquariums ammonia (once past the initial "cycle"), nitrite and
nitrate
are easily controlled by frequent partial water changes.

Simplify!
-Chris-