Science trumps Gwyneth again.
More like a tie, Dave! My chemistry knowledge is poor, but the assertion that lemon juice (because it is acidic) nixes all the (supposed) benefits of alkaline water is not very scientific either. It's all a little more complicated than that: A food that is pre-digestion acidic may still lead to alkaline results in the body in and after the process of digestion/metabolization.
https://www.healthline.com/nutrition/lemon-juice-acidic-or-alkalineNow I'm not advocating alkaline diets - the only pH values I give a
flying swimming f*** about are the ones in the water of my garden pond because of the effects a too low or too high pH value can have on my beloved sturgeons, tench, catfish, carp, Koi, goldfish, bass (the fish kind) and golden orfe (plus a dozen other species - I like variety in my pond, Koi fish ghettos bore me to tears). But since this forum of fora is devoted to the scientific truth, Dave's old flame should only be knocked for the
really silly stuff she does. Lemon juice + alkaline water is not as bad as steamed jade eggs. (If you only drink it that is! No other usages recommended here or - I believe - at GOOP.)
So mix your alkaline water with lemon all you want, it will be as (in)effective on your health as pure alkaline water. It will affect how alkaline your pee might be and is at the same time pretty much irrelevant for the pH value of your blood, but that is another matter.
PS:
Personally speaking, we like our pH neutral or a little on
the alkaline side!