You can add e.g. natron / baking soda / sodium bicarbonate to tap water and you have DIY alkaline water. Also helps to soften hard water, as calcium carbonate

You can add e.g. natron / baking soda / sodium bicarbonate to tap water and you have DIY alkaline water. Also helps to soften hard water, as calcium carbonate falls out of solution - which is then filtered in the coffee filter when brewing with a pour-over. No tinkering with the Britta filter required! :D