Brazilian Clay Water Filter health benefits
uaicentral.com
uaicentral.com
As for changing the water to be alkaline, that means it must add a chemical to your water, how much will that last and what chemical you you be drinking then?
I think you're right about some build up over time in the clay as it must retain some impurities. It's pretty common to clean it every once in a while to prevent that build up, at least that is what's mentioned by Brazilians that have used this filter for decades