Re: High pH, hard water.
To: Aquatic-Plants at actwin_com
Subject: Re: High pH, hard water.
From: psears at NRCan_gc.ca (Paul Sears)
Date: Sun, 22 Sep 1996 16:58:57 -0400 (EDT)
In-Reply-To: <199609201939.PAA13559 at looney_actwin.com> from "Aquatic-Plants-Owner at ActWin_com" at Sep 20, 96 03:39:01 pm
> From: Ken Wilson <wils0153 at maroon_tc.umn.edu>
> Subject: Please Help Me (I am in trouble)
> The problem is that my PH is very high (8.0-8.5). My tap
> water is extremely hard and has a 7.5 PH.
If the water is extremely hard, it is not at all surprising
that the pH is high. Look at the FAQ table for pH vs CO2 concentration
for different water hardness (bicarbonate hardness, that is).
If you reduce the pH with a strong acid, you form CO2 from some
of the bicarbonate ions present, so the pH you get immediately
is lower than where you end up when the CO2 has left the water.
If you keep adding acid, you eventually reduce the bicarbonate
concentration to the point where you get the sort of pH you
I use very considerable dilution of my very hard water
with R.O. water _and_ CO2 fertilization to get the pH down to
6.7 or so. If I leave mine alone (no gravel, even) I get a pH
of over 8.
Paul Sears Ottawa, Canada