African Rift Lake Chemistry
Contents:
- [Rift][Chemistry] Water treatment for Tanganyikans
by jamesb-at-sco.COM () (Wed, 17 Feb 1993)
- [Rift][Chemistry] Water treatment for Tanganyikans
by jimh-at-ultra.com (Jim Hurley) (Tue, 16 Feb 93)
- Rift Lake Water Chemistry
by ct1549-at-u.cc.utah.edu (Clark Timmins) (3 Nov 1993)
- Tanganyikan Water Chemistry
by taf1-at-cornell.edu (Tom Fredericks) (Tue, 2 Nov 1993)
- Need recipe for Rift Lake water.
by (e-mail) (Erik Olson) (6 Mar 1995)
- Marine Salt in Malawi Tank?
by orly-at-ti.com (Orlando Garcia, Jr.) (26 Apr 1995)
- Tanganyikan water chemistry (long)
by crom-at-cris.com (Crom) (Tue, 29 Oct 1996)
- African Rift Lake chemistry
by Crom <crom-at-cris.com> (Sun, 12 Jan 1997)
- Salt for Rift Lake Cichlids
by orly/ti.com (Orlando Garcia, Jr.) (5 Jan 1996)
- Something in the Krib
by Grant Gussie <Grant.Gussie/megasys.com> (Mon, 27 Apr 1998)
- RE: Something in the Krib
by Grant Gussie <Grant.Gussie/megasys.com> (Mon, 27 Apr 1998)
by jamesb-at-sco.COM ()
Date: Wed, 17 Feb 1993
In article <1993Feb16.175506.276-at-ultra.com> jimh-at-ultra.com (Jim Hurley) writes:
>This weekend I started up two tanganyikan cichlid tanks and I was
>wondering if people would post their experiences with
>making suitable water.
>
>Another used this:
> 20 gallon tap
> 2 Tablespoon Epsom salts
> 1 teaspoon Seachem Marine buffer
>
>I made a quick batch for my new fish from stuff I could pick up at our
>local food store: Sea Salt for cooking (sea salt, magnesium carbonate);
>No Salt (potassium chloride); Epsom salts (magnesium sulfate); and
>calcium carbonate (I had this laying around).
At the PCCA meeting last Saturday, our speaker cautioned against
using Epsom salts (magnesium sulfate). He claimed that the
carbonate form of magnesium is far superior, as the sulfate
form is likely to cause a condition "akin to acid rain". I'm
not a chemist, and I sure don't want to take a chance of
making my tanganyikan tank water acid, so I'll heed his
advice.
by jimh-at-ultra.com (Jim Hurley)
Date: Tue, 16 Feb 93
This weekend I started up two tanganyikan cichlid tanks and I was
wondering if people would post their experiences with
making suitable water.
I have two other postings that talked of this. One person
used this recipe:
5 gallon tap
1 teaspoon Tropic Marine Cichlid Salt
1 teaspoon Instant Ocean
Another used this:
20 gallon tap
2 Tablespoon Epsom salts
1 teaspoon Seachem Marine buffer
I was thinking of using a combination of
Instant Ocean, magnesium carbonate, potassium chloride, and
calcium carbonate.
I made a quick batch for my new fish from stuff I could pick up at our
local food store: Sea Salt for cooking (sea salt, magnesium carbonate);
No Salt (potassium chloride); Epsom salts (magnesium sulfate); and
calcium carbonate (I had this laying around).
--
Jim Hurley --> jimh-at-ultra.com ...!ames!ultra!jimh (408) 922-0100
Ultra Network Technologies / 101 Daggett Drive / San Jose CA 95134
by ct1549-at-u.cc.utah.edu (Clark Timmins)
Date: 3 Nov 1993
A few days ago somebody was asking about Tanganyikan Water Chemistry. I
was pretty busy. Now I've got some time. Hope it's not too late to help.
Here goes...
Malawi water chemistry is fairly straightforward, and, truth to tell,
pretty boring. Tanganyika is around all sorts of (non-basaltic)
volcanoes, and as such picks up so quirky chemistry. Also, Tanganyika is
incredibly stable in most ways, and never really "turns over," like most
lakes. As such, its depths are completely anaerobic and (recent theory
holds) is currently forming a petroleum deposit (that will be ready to
drill in a few million years).
Tanganyika is huge. When we discuss water chemistry we assume we're
talking about the lake's upper 20 or so meters, and far away from a river
(which changes the local chemistry greatly). PH of Tanganyika is 7.3 -
8.0, which is sorta basic. Malawi, by comparison, is 7.7 - 8.6, which is
getting up there. Tanganyika is 10 - 12 *dH (German degrees
hardness--don't have the right symbol on my terminal), which is slightly
to moderately hard (= about 150 - 200 mg/L CaCO3 or equivalent). Malawi
is 6 - 10 *dH, with is moderatly soft to slightly hard. Most aquarists
think these lakes are "very extremely hard" water. This is not so.
Hardness is defined as the concentration of multivalent metallic cations
in solution. This DOES NOT include Na+, since it's NOT multivalent).
Hardness is composed of carbonate harness and non-carbonate hardness. If
your kit tests for carbonate hardness ONLY, you won't be getting a true
reading of TOTAL hardness, which in Tanganyika is important. Check this.
CaCO3, for example, would contribute to carbonate hardness, but CaCL2
would not, since it has no carbonate. The term "carbonate" hardness can
be somewhat misleading. Remember--MULTIVALENT only.
In solution, each cation "+" is matched by an anion "-", so the "equation"
balances out. Here is the (more or less) exact compositions:
Cations Anions
Tanganyika 35% Na+ 25% Cl-
30% Mg++ 2% SiO3--
10% Ca++ 13% SO4--
25% K+ 60% CO3--
Malawi 73% Ca++ 88% CO3--
27% Mg++ 12% SiO3--
Where: Cl- is Chloride Na+ is Sodium Mg++ is Magnesium
CO3- is carbonate K+ is Potassium SO4-- is Sulphate
Ca++ is Calcium SiO3-- is silicate
Clearly, Tanganyika is much more complex than Malawi, especially since 60%
of its Cations do NOT contribute to its hardness.
There is no simple recipe for "making" tanganyikan water (unless, I
suppose, you start with distilled water). You must first know what your
local water contains--most likely in the States a high degree of limestone
or dolomite (probably both), which means you're starting with some
magnesium and calcium cations, and lots of carbonate anions. Some easy
sources of various compounds are:
"Gravel"--non safe, riverine (river washed) gravel--CaCO3 and/or MgCO3
Gypsum: CaSO4.2H2O (two waters) --or-- Anhydrite CaSO4 (no waters)
Dolomite: MgCO3
Limestone: CaCO3
Olivine MgSiO3 (this is rare and won't readily enter solution, however).
Note that adding just MgSo4 (magnesium sulfate) will NOT make tanganyikan
water, but assuming that you're starting with CaCO3 in your water, it
comes sorta-kinda close. Adding ENOUGH SiO3 for Malawi water would be hard.
(In fact, I'd like some feedback on this--I feel this might be incorrect,
as this seems like a HUGE amount of silicates to be in solution.)
Other sources: Adding KOH (potassium hydroxide) or NaOH (sodium
hydroxide) would add the appropriate cation (not enough, but some) while
having the added benefit of raising pH. NOTE, however, that as pH rises,
bicarbonate dissociates into H and CO3 (carbonate). Since carbonate is
not as soluble (or even close) as bicarbonate, it will precipitate out,
taking the divalent metallics with it, such that the water will "soften"
very quickly. This starts at pH 8.3 and higher, and is especially
pronounced at pH values of 9. At pH 10, carbonate concentration exceeds
bicarbonate!
Also, as pH rises, the percentage of metabolites dissolved as ammonium
goes down, and those dissolved as ammonia go up. This is why cichlids
can't handle ammonia (higher pH values). Note that ammonia is NH3, and
NH4+ is correctly termed "ammonium." Most/many aquarium books call NH4+
ammonia, which is incorrect.
Finally, don't confuse any of this hardness business with Alkalinity,
which is simply any concentration of ions that neutralize H (simple, once
you think about it). This includes CO3--, HCO3-, and OH-. There are
other rare ones, but if you have these you probably don't have fish.
There are also a few other multivalent metallic cations that affect
hardness, but these should be rare in aquaria. They are Fe++ (reduced
iron), Mn++ (reduced manganese), Sr++ (strontium), and Al+++ (aluminum).
I wouldn't recommend using these to increase hardness, however, as they
are mostly toxic to fish.
In metrics, 100 mg/liter = english 100 ppm (so 1 mg/L = 1 ppm). These
concentrations can help you to get your dH right, and hence to make sure
that your dissolved solids are correct.
And then, after all this work to approximate tanganyikan water you should
be aware that some studies on tanganyikan fish indicate that a few of
the species
studied do BETTER, grow BIGGER, spawn MORE frequently, spawn LARGER
clutches, and have HIGHER infant survivability in water which is more like
Malawi water, and LESS like tanganyikan water. By and large, it is my
personal opinion that pH is the most important factor, and dissolved salts
are secondary considerations.
Note that it will be virtually impossible to "make" tanganyikan water,
because of some of the "weird" combinations of anion/cation you would need
to get. You could do it, given a sufficiently large wallet, but it would
be hard. This is what makes Tanganyika such a fascinating lake, eh?
Good luck with those cichlids. Beautiful fish, aren't they?
Any other questions? We know all, we tell all, we are the:
*----------------------------------------------------------*
| |
| UTAH TROPICAL AQUARIUM HOBBYISTS |
| |
| Brad Lauchnor Clark Timmins |
| internet account Clark.Timmins-at-m.uu.utah.edu |
| pending -- will |
| post shortly |
| |
| UTAH TROPICAL AQUARIUM HOBBYISTS |
| |
*----------------------------------------------------------*
by taf1-at-cornell.edu (Tom Fredericks)
Date: Tue, 2 Nov 1993
In article <157580-at-netnews.upenn.edu> zartler-at-a.chem.upenn.edu (Edward
Zartler) writes:
>From: zartler-at-a.chem.upenn.edu (Edward Zartler)
>Subject: Tanganyikan Water Chemistry
>Date: 26 Oct 93 22:08:18 GMT
> Dear All,
> I have a 29g hex tank attempting to simulate the Tang.
habitat
>but, One problem I am having is that... believe it or not, the tap water I
use
>in the tank is not hard enough. So, I have been adding stuff called
>Aquacichlid to the tank. Some kind reader of this newsgroup said that all
>that
>is is MgSO4. MY question is:
> Does anyone really know the actual chemical composition of
>the Tang. waters????? My cichlid books don't say... either flawed books or
>nobody really cares. But, I do.
> I am a graduate student in chem, so if I can get the proper water
>conditions for all of my lovelies. I would love to do this.
>So please if anybody knows, or knows where I can find out please help .
>*****************************************************************************
*
>Teddy
>Zartler-at-a.chem.upenn.edu
>Univ. of Pennsylvania (The Cool Ivy... According to Seventeen Magazine)
>Go to Grad School... Avoid Reality.
>This Message brought to you by Ellipsis Inc.
> "When your sentence trails off... we finish it."
>*****************************************************************************
*
Teddy,
I dragged a portion of the following article from my archives:
|Newsgroups: alt.aquaria,rec.aquaria
|Subject: Recreating Lake Tanganyika water with the right salts
|Message-ID: <1991Sep27.203202.15002-at-agate.berkeley.edu>
|From: thuan-at-monsoon.Berkeley.EDU (Thuan Nguyen)
|Date: 27 Sep 91 20:32:02 GMT
|
|
| CHEMICAL ANALYSIS OF LAKE TANGANYIKA WATER
|
| by Dr. Kuferath (in Brichard's Fishes of Lake Tanganyika)
|
| Salt mg/L
| __________________________
| Na2CO3 anhydrous 125
| KCl 59
| KNO3 0.5
| Li2CO3 4
| CaCO3 30
| MgCO3 144
| Al2(SO4)3 * 18 H2O 5
| K2SO4 4
| Na2SO4 1
| FeCl3 * 6 H2O 0.5
| Na3PO4 * 12 H2O 0.4
| Na2SiO3 13.5
| __________________________
|
- Tom Fredericks
by (e-mail) (Erik Olson)
Date: 6 Mar 1995/1996
Newsgroup: rec.aquaria,alt.aquaria
deadfish-at-netcom.com (Bruce Hallman) writes:
>Eric Hanneman (erichh-at-efn.org) wrote:
>: One tablespoon epsom salt, one teaspoon sea salt, one teaspoon baking soda,
>: per 5 gallons. If your water is distilled, that is.
>Thanks Eric, And what is the goal, measured in Carbonate Hardness,
>General Hardness, and pH? Bruce.
The nice thing about African Cichlids is that they will tolerate a
wide range of conditions. Like any pH above 7.5 (though there's a guy
in Seattle who keeps N. brichardi in native water (pH 7.0, KH<1 GH=1).
When I was trying to make my own custom Lake Tanganyika, I did some
quick checking in the hobby literature & found a breakout of the
dissolved minerals (in a pie chart!). For Lake Tanganyika, the
positive ions are mostly magnesium and sodium, with a little bit of
calcium and potassium. Negative ions are mostly carbonates, with a
little bit of chloride. So I made up the following formula (by
weight):
22 gm NaHCO3 (baking soda, grocery store)
12 gm KCl ("No salt", grocery store)
24 gm MgCO3 (magnesium carbonate, chem supply house)
6 gm MgCO3+CaCO3 (Dolomite-Limestone, garden supply)
I still use this mixture, but have subsequently read that virtually
ANY buffering system that raises the pH (and subsequently KH) and GH
should be OK.
Oh, and for Malawi, the same reference shows a much more complicated
set of dissolved ions, and the dominant positive ion Ca instead of Mg.
People are better off inventing their
own instead of trying to track down all the "true" Malawi salts.
>P.S. Why epsom salt?
It's darn cheap, and you can buy it in a grocery store. It raises GH
(but not KH, because it's a sulfate instead of a carbonate). Most
commercial mixes contain a large amount of epsom salt. I have
heard unsubstantiated rumors that using it is akin to having acid rain
in one's tank, though.
>P.P.S. Would it be OK to premix these three ingredients together in
>their powdered forms, or would they tend to segregate?
Mix the powder. Should work great.
- Erik
--
---
Erik D. Olson The Job-o-meter:
(e-mail) eh... a two-monther
the computer is back...
by orly-at-ti.com (Orlando Garcia, Jr.)
Date: 26 Apr 1995
Newsgroup: alt.aquaria
Dave,
Holy bitbucket Batman, in article <19APR199512034246-at-ubvms.cc.buffalo.edu>,
v011l6fc-at-ubvms.cc.buffalo.edu says...
>
>One of the staff at my local fish store said that I should put 1 tsp./gallon of
>marine salt in my Malawi Cichlid tank. He said that the salt and trace
>elements were good for the fish. But after reading Loiselle's book on African
>Cichlids, I'm beginning to wonder if the fish store clerk knew what he was
>talking about. Loiselle said that salt isn't necessary, and his analysis of
>Malawi water reveals high levels of Calcium and Carbonate ions/anions, but few
>other important marine ions.
If the Loiselle you mention is "The Cichlid Aquarium," I strongly suggest you
re-read the section on water conditions *slowly* and *with no distractions*. He
explicitly states that the most overlooked elements in [general] Cichlid water
are Pottasium and Magnesium and even suggests some ways to go about emulating
their presence. I keep Tanganyikans and have studied the lake analysis in
great detail and as it turns out, Sodium is a major player as well, which _is_,
of course, provided by salt. I strongly suggest you check out your city water
analysis before you start dumping stuff into your tank. Loiselle does state "in
areas where" ... "concentartions are weak" ... "may be used" ... "at a rate of"
... or somthing like that.
>
>So what's the best route to go? Salt/no salt? Rock salt/marine salt?
>
>Loiselle also wrote that it was important for the Malawi cichlids to have 2 or
>more females for every male, since they were polygamous mouthbrooders. The
>clerk did not raise this issue either, and sold me pairs of Malawis. Is there
>a "right answer" to this either?
Not all shop keepers are experts on Cichlids, but usually each shop has at least
one person that knows what the hell they are talking about, or even better yet,
one that openly admits that they do not know how to answer your question. You
will find that your grouping issues depend on the personalities of your specimens
and how much dither/target your specimens find in their tank mates. I think that
you can draw from Loiselle that when your male is whipping up on your female,
give a few more females to spread the load.
Good luck,
--
Orlando Garcia, Jr. Dallas, Texas Opinions expressed are not that of TI's
orly-at-ti.com Heaven forbid they would ever coincide!
by crom-at-cris.com (Crom)
Date: Tue, 29 Oct 1996
Newsgroup: rec.aquaria.freshwater.cichlids
Hello all...
I've been working on formulating my own salt mix for Tanganyikan
water, based on a breakdown of the prevalent anions and cations in the
lake, and data from my municipal water utility. The dilemma I'm
facing is that my results seem to indicate that the mixes others are
using are massive overkill!?! What I'm wondering is if my chemistry
is right, I suppose.
I ran across a compendium of articles on the Krib relating to
Tanganyikan water chemistry. There were two sets of data contained
therein regarding the subject:
Breakdown 1 (view this table in a fixed pitch font, with tab spacing
of 8 spaces, or squint):
Cations Anions
------- -------
35% Na+ 25% Cl-
30% Mg++ 2% SiO3--
10% Ca++ 13% SO4--
25% K+ 60% CO3--
This breakdown is echoed by a chart I have in Loiselle's
FG_to_African_Cichlids, but from which post the poster obtained it.
(Note: Please give sources when posting data.)
Breakdown 2 (by Dr. Kuferath, in Brichard's FoLT):
Salt mg/L
____________________________
Na2CO3 anhydrous 125
KCl 59
KNO3 0.5
Li2CO3 4
CaCO3 30
MgCO3 144
Al2(SO4)3*18H2O 5
K2SO4 4
Na2SO4 1
FeCl3*6H2O 0.5
Na3PO4*12H2O 0.4
Na2SiO3 13.5
(Q: I'm assuming that the notation *xH2O means the compound is
hydrous. When calculating the atomic mass, do I add in the mass of an
appropriate number of H2O molecules?)
I'm assuming the first data set is more accurate, since it is based on
a larger data set, and is more recent. Also, it's easier to work
with. :) My blundering analysis of the second set gave values pretty
close to the first set, as well.
The first big bungle I made (and this is a word to the wise) was in
assuming that the percentages given in the table were relative
concentrations of the ions themselves (i.e. there is 2.5 times as much
K+ as Ca++). If this were true, the lake would be negatively charged.
:) The percentages given are of charge due to the presence of these
ions. I'll combine both types of data in this here chart:
Cations %charge %total Anions %charge %total
----------------------------------------------------------------------
Na+ 35 44 Cl- 25 40
Mg++ 30 19 SiO3-- 2 2
Ca++ 10 6 SO4-- 13 10
K+ 25 31 CO3-- 60 48
At first I was boggled -- I didn't know the specific gravity/density
of the water. How would I go on? Then I did a big Homer Simpson
*DOH!*. I knew GH (sum of Mg and Ca (primarily) concentrations), so I
could base it all on that! I shot for a value of 150 ppm CaCO3 (8.4
dH) GH. (Low, I know, but within given ranges. My fish already seem
happy enough. This is just sport. :]) By my calculations, this
would give a KH of 288 ppm CaCO3 (16.1 dH).
Well, I formulated my recipe, went at it, and was successful. If
anyone would like to see the process I went through, I can post that,
as well. I used baking soda (NaHCO3), epsom salts (MgSO4), and salt
substitute (KCl). My problem is that I had to add more sodium and
chloride than is present in the lake in order to get proper K+ and
CO3-- (HCO3-) levels. I'm planning on looking into Muriate of Potash,
which I BELIEVE is KaHCO3 to clear this up. Can anyone verify that?
I won't post the exact amounts, since this should be dependent on
initial water conditions. I will say that they are MUCH less than
I've heard others use (shoulda figured that out before I bought 4# of
epsom salts -- guess i can always soak my head), which brings me to
the next part of my maxipost.
One post I saw (from the compendium on the Krib) -- the only one which
assumed one started with distilled water -- indicated one should use
one tablespoon of epsom salt (et al) per 5 gallons. This doesn't
sound right to me, and this is why (please check my calculations):
1 tbsp MgSO4 (epsom salts) = 15ml MgSO4.
5 gal H2O = 18.9l H2O.
This gives us a concentration of 15ml MGSO4 / 18.9l = 0.79 ml/l MgSO4.
The density (specific gravity) of MgSO4 is 2.66 kg/l = 2660 mg/ml,
which means 0.79 ml/l MgSO4 = 2100 mg/L MgSO4 (to some this sounds
right out already, I'm sure, but I'll keep going).
Now we need to convert to this to an equivalency in ppm CaCO3. The
(approximated, based on atomic #) molecular weight of MGSO4 is 104
g/mol. This gives us 2100 mg/l MgSO4 = 20 mmol/l MgSO4.
To get an equivalent in ppm CaCO3, we multiply by the molecular mass
(approximated at 100 g/mol) of CaCO3, right? This give us 2000 mg/L
CaCO3 = 2000 ppm CaCO3 = 112 dH!?!
Am I wrong somewhere in my calculations? I'd like to be, since the
general consensus seems to be that MUCH more than what I'm adding is
used by most. Thing is, that when I tried this with a 5 gallon water
sample (adding my formulation), I ended up with 9dH GH, 15 dH KH, and
somewhere in the low 8's pH (I can't READ the red/oranges in that
damned test kit!), which is right about where I wanna be....
Well, that's all (wasn't it enuff?)
Brian T. Forsythe
crom-at-cris.com
(BTW, this is being crossposted to the cichlids mailing list, and to
r.a.f.c.)
by Crom <crom-at-cris.com>
Date: Sun, 12 Jan 1997
Erik,
I must say that your archiving of my post on DIY Tanganyikan
salt was a huge ego boost. :)
I wanted to make a remark that you may want to add in some way. Epsom
salts are actually MgSO4*7H2O, so my calculations were incorrect in
that matter. I BELIEVE that is the only mistake therein. You don't
happen to know the term for substances like MgSO4 that bond with water
molecules, do you? Is that a crystalline structure?
Thanx much,
Brian T. Forsythe
crom-at-cris.com
Every picture is not worth a thousand words; besides, I think I'd rather have the thousand words.
by orly/ti.com (Orlando Garcia, Jr.)
Date: 5 Jan 1996
Newsgroup: alt.aquaria,rec.aquaria
Holy bitbucket Batman, in article <4c50at$c9u-at-eri.erinet.com>,
crom-at-erinet.com says...
>
>Should I add aquarium salt to my African Cichlid Tank? If so, in what
>proportion?
I wish I had .05 for evry time I heard that question and another .05 for
every time I answered it! The bottom line is that if you are in doubt as
to what to add to your water, there are sound scientific ways to figure it
out - this is not an area that requires any judgement whatsoever. Get a
local water analysis and compare it to the lake in question. Use household
products to supplement the missing salts in the appropriate quantities. Of
all the major salts present in Tanganyika, for example, Sodium (as in
what you get from table salt, NaCl) is one of the lesser players! You would
do much better to worry about Calcium, Magnesium, and Potassium, each of
which contributes about 100+ mg/L to the lake's water. And even if you did
want Sodium, why not get it from baking soda and get the carbonate hardness
which you also need rather than the useless chlorides?
I just love hearing folks make recommendations on salt addition for African
tanks with no sound scientific reasoning to back it up. Hell, even
Loiselle speaks of adding Epsom and No-salt to get the Magnesium and
Potassium ions typically present in East African rift lakes and he does so
without any specific regard to local water quality! I suggest we eliminate
all experimentation from this matter and use a calculator instead!
HIH,
Orly
Dallas, Texas Opinions expressed are not those of TI's
orly-at-ti.com Heaven forbid they would ever coincide!
by Grant Gussie <Grant.Gussie/megasys.com>
Date: Mon, 27 Apr 1998
To: eriko/elmer.wrq.com
Hi:
There is a reprinted *.aquaria letter in the Krib at
[right here - Editor]
which I was perusing and think needs some comment since people may be
mislead by it . The letter
Tanganyikan water chemistry (long)
describes calculations for water hardness when Epsom salt is added.
The method is sound, but he made two errors. Epsom salt is magnesium
sulphate pentahydrate, or MgSO4 + 7(H20), and it has an atomic weight of
246.3 amu and a density of 1.667 g/mL. He used the numbers 104 amu and
2.66 g/mL, which according to my handy-dandy CRC Handbook of Chemistry
and Physics is correct for magnesium sulphate, but not for magnesium
sulphate pentahydrate. Putting in the correct numbers, I get 1
tablespoon per 5 US gallons yields an increase in hardness of 534 mg/L
CaCO3, or 30 GH. (He gets 112 GH).
Thought I'd mention it.
Cheers!
Grant
by Grant Gussie <Grant.Gussie/megasys.com>
Date: Mon, 27 Apr 1998
To: Erik Olson (e-mail)
Thanks
I made one mistake though; I meant magnesium sulphate
heptahydrate (7), not magnesium sulphate pentahydrate (5).
> -----Original Message-----
> From: Erik Olson [SMTP:(e-mail)]
> Sent: Monday, April 27, 1998 4:50 PM
> To: Grant Gussie
> Subject: Re: Something in the Krib
>
> Hi Grant,
>
> Thanks. I'll at least pop in your correction. If I'm feeling real
> good
> that day, I'll try to put in a link to your correction from the
> original
> article.
>
> - Erik
>
>
> On Mon, 27 Apr 1998, Grant Gussie wrote:
>
> > Hi:
> > There is a reprinted *.aquaria letter in the Krib at
> > [here - editor]
> > which I was perusing and think needs some comment since people may
> be
> > mislead by it . The letter
> > Tanganyikan water chemistry (long)
> > describes calculations for water hardness when Epsom salt is added.
> > The method is sound, but he made two errors. Epsom salt is magnesium
> > sulphate pentahydrate, or MgSO4 + 7(H20), and it has an atomic
> weight of
> > 246.3 amu and a density of 1.667 g/mL. He used the numbers 104 amu
> and
> > 2.66 g/mL, which according to my handy-dandy CRC Handbook of
> Chemistry
> > and Physics is correct for magnesium sulphate, but not for magnesium
> > sulphate pentahydrate. Putting in the correct numbers, I get 1
> > tablespoon per 5 US gallons yields an increase in hardness of 534
> mg/L
> > CaCO3, or 30 GH. (He gets 112 GH).
> > Thought I'd mention it.
> > Cheers!
> > Grant
> >
> >
>
> ---
> Erik Olson
> eriko at wrq.com
The Krib
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