The two are linked. At a known level of CO2 (i.e. what you get from the
Atmosphere) as KH falls so Ph will fall with it. In other words if you want
to bring down the Ph to 7 then you need to reduce the Kh which you can do
with Peat, or bogwood etc.

However, two issues...

a) As Kh approaches zero so Ph becomes unstable and can crash (to 5 & below)
with disasterous results.



I do and don't agree with the above statements.

IIRC
a high KH (70 ppm) will raise pH, but KH, within normal ranges, acts as
a stabilizer (buffer) for pH, the lower the KH the more drastic the pH
swings maybe. An average KH 30-70 ppm will keep large (rapid) pH swings
from happening due to outside factors. A KH of lower than average can
allow pH swings caused by something as simple as the aquariums lights
on/off cycle.

any chemists out there that can translate that into a more
understandable language?

I used to work as a swimming pool technician, so if my chemistry is off,
think twice before going into a public pool.

Kris