[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
RE: MURATIC ACID & pH reduction
-----Original Message-----
From: owner-killietalk at aka_org [mailto:owner-killietalk at aka_org]On
Behalf Of Tyrone Genade
Sent: Thursday, February 14, 2002 3:32 AM
To: killietalk at aka_org
Subject: Re: MURATIC ACID & pH reduction
On 14 Feb 2002, at 2:07, Tranquility Base wrote:
> I have heard from people who are as cheap as I am and/or keep large
> numbers of tanks and have alkaline tap or source water that they use
> muratic acid to lower the pH.
Is the water bufferred by carbonate hardness or is there a lot of
free Calcium and such?
The object of the exercise is to take the water from pH 8.3 to pH 7.3. I
would like to keep as much hardness as possible. Too soft means too many
water changes. Both carbonate and other hardness are not too high. The
water is not soft but not what most people would call hard. I'll have to run
another test tomorrow.
> Has anyone ever used this acid? Do you
> have any suggestions as to how much of what concentration is
> appropriate to achieve a certain effect. Any pros or cons to it?
If you have a pH of 8 and want to to bring it down to 6 then you
will need about 0.01 mols of acid per litre of water. Muratic acid is
HCl. The most concentrated you can buy it is 32% (10.8 mols/litre)
but I wouldn't touch this stuff... Try to get a 3.2% solution (about
1 M) in which case you would have to add 10 ml to every litre of tank
water.
I would adjust the pH before the water reaches the tank...
Adjusting the water once it is in the fish tank is clearly wrong. I prepare
my water in a 20 gal long tank. When the water is correct for the purpose I
refill the fish tank.
Now the danger: if you have a lot of sodium in the water you will end
up with about 0.01 mols of NaCl per litre or 0.57g per L or 0.057%
solution of NaCl. The more you play with the pH the greater the risk
of increasing the NaCl concentration too much. Many experiments have
been ruined because someone played with the buffer too much and ended
up with more salt in the reaction vessel than what there is in the
equivalent volume of sea water.
So that's where the Cl goes! I was actually wondering about that. Table salt
is actually better than some of the molecules I thought up. So it would seem
that I should add less salt to my water preparation than I do now. Saves on
salt. Not tragic. As Na in the water should already be bound with something
else. I would hope that some of the extra Cl should flash off or is this
wishful thinking?
In any event, I have a hydrometer, and will test the specific gravity of the
product. Thanks for the heads up!
A second problem is the nature of the buffering. The 0.01 was worked
out presuming that all the buffer is already in solution. In the case
of Ca or Mg carbonate the is still alot more buffer that what is
seen. The best would be to take a litre of water, sit down with a pH
meter and play around keeping track of how much acid you are adding.
Remember that the physiological NaCl concentration is around 0.135 M
(0.78% m/v).
I have been using some ancient Sodium Biphosphate. 2 tsp per 18 gal drops
the pH from 8.3 to 7.0 within 24 hours it bounces back up to 7.3. I have
had this stuff around for years, since I lived where the water was very
alkaline. I had great water here, but since the water company started
playing games I have been going through the Sodium Biphosphate fast.
If you really want to keep soft water killies buy a bale of peat
(canadian or Michigan as it is the best as far as reducing pH and
hardness) and filter the water over peat. You will also have lots of
cured peat for you nothos.
This is not a bad idea. But way too much work, time, expense etc. I have too
many tanks to start a project of that magnitude. My tap water has been pH
7.3 and soft for years. But there is apparently some kind of a water
shortage going on here in the Northeast U.S. and I am now on the water
system's old wells. The pH is now 8.3 and a somewhat harder. I suppose I
could acclimate most of my fish to pH 8.3 as most are Nothos anyway, but 7.3
has worked fine for a long time and I hate to change what works.
Hopefully some day I will get my old water back on a regular basis, until
then it better living through chemistry.
Thanks for the insight Tyrone.
Peace,
~RJ~
Bye
Tyrone Genade
tyronegenade at yahoo_com
http://www.tyronegenade.0catch.com
*************************************************************
P450 Lab, Biochemistry Department
University of Stellenbosch, 7602, South Africa
Ph: +27-021-808-5876, fax: +27-021-808-5863
**********************************************************
"No, the LORD has told us what is good. What He requires
of us is this: to do what is just, to show constant love,
and to live in humble fellowship with our GOD."
Micah 6:8
---------------
See http://www.aka.org/AKA/subkillietalk.html to unsubscribe
Join the AKA at http://www.aka.org/AKA/Applic.htm
----------------------------------------------------
Sign Up for NetZero Platinum Today
Only $9.95 per month!
http://my.netzero.net/s/signup?r=platinum&refcd=PT97
---------------
See http://www.aka.org/AKA/subkillietalk.html to unsubscribe
Join the AKA at http://www.aka.org/AKA/Applic.htm
References: