Just a little City of Milwaukee tap water info for the OP
Milwaukees water source is Lake Michigan, and very stable body of water
Tap water pH averages between 7.6 and 7.8, depending on the season,
hardness also varies slightly with the season, but is generally considered medium hard..
tI has a decent buffering capacity (alkalinity) of about 90ppm, which helps prevent pH crash if water changes are adequate.
Nitrate is usually < 1ppm straight from the tap
You can find out all tested parameters ad nauseam on the Milwaukee water works web site, by clicking on the Mil. gov EPAs yearly water quality Ereport.
Many of the general parameters are also on the info that comes with the water bill.
All this info is great for choosing the type fish applicable to an aquarium in the City of Milwaukee, and surrounding suburbs serviced by the Mil Water Works.
Fish that prefer neutral to high pH naturally do well,
as do those from medium hard to hard water, with moderate mineral content
Tap water is disinfected with Cloramine, and Ozone. and depending of proximity to the water plants, Chloramine residual is usually about 1 ppm
The ozone creates a highly saturated oxygen level