Quick Answer
pH measures acidity on a 0-14 scale, with 7 neutral. Municipal water is typically kept near neutral (roughly 6.5-8.5). For the shower, pH is a minor factor compared with chlorine, chloramine, hardness, and temperature.
Problem
pH is one of the most misunderstood water numbers, and some product marketing overstates its importance for shower water.
Product Recommendation
For shower-water experience, prioritize chlorine/chloramine reduction and sediment over pH. ZOOSHEN systems target the substances that matter at the shower. See /water-science/chlorine-vs-chloramine.