I use distilled and I basically know how to ADD salts to a point. My observation was that the website doesn't offer much of a choice in picking a water profile. I'm sure I need to learn the different name's they have listed. I'm brewing a maibock and don't see a malty amber choice for instance.
Okay, gotcha, I look at it like cooking. There is some trial and error, but some basics to follow.
You want to get your Ca up in the 100 area
Keep magnesium from getting to high, In the teens max.
Na could be higher than that, maybe into the 40's
Then you want to consider your Chloride to Sulfate ratio based on what you are brewing.
For malt forward beers like stouts, porters, and NEIPA, you want a chloride:sulfate ratio of 2:1, or as much as 3:1.
For a hop forward beer you would want the opposite ratio, but I wouldn't go any higher than 1:2.
For Amber's, and other less hoppy beers you would want a more balanced profile with a ratio of 1:1.
Much like with a beer recipe itself in that there is no right or wrong recipe for a particular beer, there is also no right or wrong water profile (seasoning) for any particular beer.
I don't use the software here so I am not familiar with what you might be seeing in the water calculator. If you like Icould post some screen shots of typical water profiles that I use for different recipes.