Re: about KH buffering capacity

[Roger Miller <rgrmill at rt66_com>]

BC wrote:

> Peat do not "invalidate" KH buffering capacity.  Peat merely releases humic
> acids which will lower the KH. KH, pH and CO2 relationship do not get 
> affected.

It is possible for peat to invalidate the KH-pH-CO2 relationship.  Peat can 
do that by releasing weak organic acids into the water that can be measured 
as part of the KH.  The KH-pH-CO2 relationship assumes that all KH is 
produced by bicarbonate.  If that isn't true the the relationship is 
incorrect.  The effect causes the KH-pH-CO2 relationship to overestimate the 
amount of CO2 in the water.

Some driftwood can cause the same effect.

While it is *possible* for peat (or driftwood) to invalidate the KH-pH-CO2 
relationship it is by no means guaranteed.  You probably shouldn't assume 
that it happens.  In fact I would guess that it happens a minority of the 
time -- especially with drftwood.  Significant problems are less likely if 
your water supply is naturally well-buffered.


Roger Miller