I'm sorry i just looked up tds using the location in your signature and it seems different area of the city has hardwater water 400+ ec vs the 120 ec you have.My tap water is relatively soft (~125µS/cm) but certainly not as soft as in my breeding tanks (~35µS/cm). Most fish are fairly adaptable. When acclimated to harder water they will not be severely impacted by it. I once saw a store that sold Cardinal Tetras that they slowly acclimated to 13ºdKH. They were very popular with hobbyists in the area where the town was on well water. Of course softwater fish don't usually breed successfully in hard water.
I'm pretty sure that i read an article that indicated that softwater fishes longevity were impacted by mineral build up in organs in harder water but maybe it is only a few specific species and not generically true or maybe the impact while measurable is insignificant ?
One thing i've been finding is a lot of tap water bred fishes wont' last in my very soft acidic environment while wild caught versions will do extremely well - i presume it is bacteria issue but perhaps there is something else happening.