[tguvot]

All those filters are specifically made for PH adjustment (you are welcome to look at specs). There are bunch of different formulations depends on how much PH adjustment is needed.

RO makes water more acidic. if water was somewhat acidic to start with, it can get more acidic or become corrosive.

[Xss3]

The spec doesn't tell you intent it tells you the resulting product performance.

Ph change is one part of the result, not the goal. The goal is water purification.

[tguvot]

i am talking here about post-filters for PH adjustment. their goal is PH adjustments

those for example https://www.freshwatersystems.com/collections/specialty-cart...

or those https://www.freshwatersystems.com/collections/filters-media?...

[bernawil]

Are you sure that it makes it more acidic? AFAIK it only outputs pure H20, should be neutral. If you feed it alkaline water you'll get "more acidic" water, but the other way if you feed it acidic water.

[tguvot]

yes. it removes calcium and magnesium and it makes water more acidic. also i think it starts absorbing CO2 making it even more acidic.

RO doesn't output pure water. if you want pure water you slap DI filter after RO membrane.

[bernawil]

you're right, a little oversight from me.