lol, I meant, if you did want those things, you'd need to be more concerned about the hardness of your water. If you just want 'normal' trops, then it's not so important, but it is nice to know so you can choose fish suited to your waterno nort really but have only been here since februaryJust roughly will do, unless you're wanting things like discus/rams or rare livebearers. Do you get a lot of limescale in your kettle or on your showerhead?