From school days, I think that 10.5 is a highly alkaline figure isn't it?
How do you guys get alkaline water from taps unless you're storing it in concrete containers in your back gardens?
The reason I ask is that I've never yet tested tap water from a city reticulated supply & found it to be anything but acidic and in the tropical fish business, the first thing they tell you to do is to balance the ph before you start to age the water and regardless of country, I've always read that "Town Water" is acidic. Rain or tank water is usually either neutral or alkaline depending on the storage (ie) concrete or plastic tank.
Perhaps the fact that when I went to school the teachers used to refer to cars as 'horesless carriages' could have a bearing.[:D][:D]
Alan S