Ha after I posted I realized I should probably do some testing to give you more specific parameters. Haven't lurked long enough, apparently. I don't know actual numbers at the moment; lost my testing kit and have yet to get a new one. I might get a chance to grab one today.
I *do* know we have a LOT of african cichlid breeders in the area, which I have always attributed to the hard water here. But I'm not familiar enough with any specifics, I just assume they are larger and require more room than I can give them.
I have successfully kept tetras of various species, pencilfish, and cories (and of course those perennial faves & easy keepers plecos, bettas, platys & mollys). I have not had luck with gourami (6 weeks max), otos (6 months max), or GBR (8 months max). My tank is fairly well planted and I do a 25% change weekly when I am not letting it fall by the wayside.
Anyway, I'll test the hardness and see what's what.