What would the ph of ro water be if it is

[a4]

aerated with outside air? Assuming the water is pure water to start with. TDS reading of 0?
Thanks
Linus

[Randy Holmes-Farley]

Pure water in equilibrium with normal air has a pH of about 5.66. But you will not be able to accurately measure that with either a pH meter or a kit. Neither can accurately measure pH in highly purified water.

[a4]

Thank you
Why can't you accurately measure ph in pure water?

[Randy Holmes-Farley]

You're welcome.

Happy Reefing. :)