If you are getting to a point where you are brewing good beer with the water you have and are starting to identify possible flaws then it is time to start thinking about water treatment
It’s already been said, don’t do anything unless you know what is in your water.
Learn the difference between Hardness (calcium and magnesium content of the water = GOOD!) and alkalinity (Carbonate/bicarbonate content = BAD!!). Just because the water companies quote both as if they are supplied completely by calcium carbonate does not mean they are the same or even equivalent to each other in any way shape or form.
Get a Salifert Total Alkalinity test kit and use it each and every time you brew . . . base your acid additions on the kit result.
Water treatment is simple, geeks like to complicate it
1) Reduce chlorine – carbon filtration or campden tablet treatment
2) Adjust alkalinity to that for the style. Generally Pale beers with a pale grist need low alkalinities (30-50ppm), while dark beers with roast / dark crystal malts need higher alkalinities (75-125ppm)
3) Adjust Calcium to a minimum of 100ppm using the flavour salts, gypsum/calcium sulphate to increase the perception of hoppiness, and calcium chloride to increase the perception of maltiness. A mixture of the two will produce a balance.
I’m not a fan of CRS or DLS as you are adding salts and ions in a fixed ratio, which may or may not be appropriate for the beer you want to brew. I use hydrochloric and sulphuric acids depending on the style I’m brewing, other people use phosphoric as it doesn’t matter what style you are brewing.