pH can have an effect on the ...
Published by Joseph Cotruvo, President at Joseph Cotruvo & Associates, Water , Environment and Public Health
pH can have an effect on the corrosivity of the water toward pipe and other plumbing materials. pH 5 is much too low and acidic. That is close to vinegar. NaOH is probably cheapest to raise pH because less is needed, but the carbonate could add some buffering stability. So if your water is very low alkalinity it might be better to use carbonate or a mix. Use drinking water grade material. NSF International is one product certifier but there are others that are equivalent. In either case the sodium increase is not significant. Bottled water parameters are not relevant because the water does not contact plumbing materials.