I currently own two brushes, both C&E and both are best badger (one is a travel brush stored in its tube).
The brush I use for every shave gets exposed to hard water (which is what I have in my home).
From time to time I will inspect the brush and notice that it has residue, probably from calcium, on the brush and where the brush meets the handle. The residue resembles barely noticeable white powder.
I rinse the brush thoroughly in warm water after every shave, shake the brush out and hang to dry in my brush stand.
Should I be doing anything else?

This brush isn't a high dollar Rooney but I would like it to last a while.