I use a Pur 3-Stage water filter attached to the sink for filtering my brewing water. The 3rd stage supposedly lets the water run over a mineral bed which imparts a "better flavor" to the water. I assume that means it's adding minerals to my water. I'm wondering if that is the case, and if so, are they minerals that will affect my water profile for brewing? Which ones? Is it adding enough to the water to make a noticeable difference?