Re: [AGA-Member] Magnesium nutrient issues

[Larry Lampert <l_lampert@yahoo.com>]

 Hi Heather,

The old Krib Archives are a goldmine of information
for those interested in doing the research. We can all
thank Erik Olson for that! 

I am not sure what part of the country you are in but
for reference purposes. My water comes from 3
reservoirs here in Dallas so it to can vary. I measure
my GH with a Lamotte kit. It comes out to around 5.5
Gh, to be exact when I do the calcium test and the
Magnesium remainder it comes out to 96-98ppm total GH
with 90-94ppm CA and around 4-6 MG. Yes, my CA:MG
ratios are way out of whack too. I use two teaspoons
of Mg2SO4 for each 30 gallons of water I change. This
gets me to about 138ppm total of which the Mg is now
around 48-54ppm. 

It is not exact since my teaspoons are not always
measured exactly level. I have not seen any
reproducible benefits from going any higher or lower
with MG ratios. IME if I keep the ratio at 1:3 or 4 it
is all the same. I have not gone any higher than 1:2
as Jeff discussed so I don't know what would happen
but I have used straight tap water and my plants did
indeed have deficiency symptoms.

The last piece of advice is to not trust test kits
implicitly. The reagents go bad over time in the best
of kits, and many pet store grade kits don't seem to
work at all. Indicator plants ie. Rotala, Ammania, and
many others will let you know if you have a nutrient
deficiency every time as long as you know what to look
for. More good info on this on the Krib and APD
archives too!

Reading your posts it sounds like you are on the right
track. Let us know how the tank progresses.

Regards,
Larry Lampert
Dallas,TX


--- Heather J Gladney <hgladney@comcast.net> wrote:

> Larry Lampert wrote:
> 
> >Heather,
> >
> >A couple of comments and a couple of questions....
> >You stated:
> >
> >  
> >
> >>>advise. dGH - dKH = additional alkaline metals
> >>>      
> >>>
> >>such as Na, Mg, and so 
> >>    
> >>
> >>>on.  One point of the difference is the soda I've
> >>>      
> >>>
> >>been adding.  Local 
> >>    
> >>
> >>>waters are alkaline but not dolomitic, so I'd
> >>>      
> >>>
> >>suspect the remaining 
> >>    
> >>
> >>>point, from the source tapwater, is also mostly
> >>>      
> >>>
> >>sodium.
> >>    
> >>
> >
> >Magnesium and Calcium are components of GH. The
> >alakaline earth metals are the would be like
> barium,
> >or other rare elements. These are not commonly seen
> in
> >measurable quantities in tap water in the US.
> >
> >As far as I remember Sodium does not add to
> alkalinity
> >anyways. 
> >
> I should have rechecked my Krib printouts (thought I
> had--must have 
> glazed over on these)  Rechecking some of the Krib's
> archived water 
> hardness posts, 16 Dec 1997 Larry Frank was saying
> that GH measures only 
> Ca and Mg, KH measures only bicarbonate and
> carbonate anions, not 
> sulfates or other anions.  He also comments that in
> most freshwaters 
> most of the cations are Ca:Mg in 3:1 ratio, but
> levels of GH and KH will 
> often be similar.
> 
> >It does of course add to TDS. If you are
> >concerned with Na levels contact your local water
> >utility and ask for a copy of their annual water
> >report.
> >  
> >
> Our is online, so I was able to yank some numbers.
> (see below).
> 
> >I am also not sure about your magnesium ratios you
> are
> >trying to chieve. CA and MG are macro elements. The
> >plants use them for osmotic balance as well as
> >consuming themin trace amounts. The ratios between
> CA
> >and MG are usually 4:1 or 3:1. I think what you
> read
> >on Chuck's page was the minimum amount of 5-10 ppm
> MG.
> >  
> >
> Sigh of relief!
> 
> >Increasing the MG will increase your GH but it will
> >NOT
> >affect your buffering capacity. If you add a
> carbonate
> >or bicarbonate like baking sode that will increase
> >your alka;inity or the ability of your ater to
> resist
> >a downward change in pH.
> >  
> >
> When I rechecked my copies of Krib posts re:
> hardness and CO2, I found 
> one water hardness post put up by Larry Frank back
> in 1997 in the CO2 
> archive of the Krib.  He said adding carbonates
> would push the 
> equilibrium back toward a more alkaline situation. 
> You're quite right, 
> it's the carbonates doing so, not the Na.
> 
> >If you are concerned with your CA:MG ratios you can
> >use Seachem's equilibrium instead of the dolomitic
> >lime and epsom salts. Equilibrium will give you a
> >correct ratio out of the jar.
> >
> Great idea, thankyou--I'm really tempted to toss
> aside the calculations!
> 
> > I would contine to use
> >Baking Soda for raising Alkialinity unless you do
> >indeed have an elevated level of soium in your
> water
> >like Cheryl does. I would not assume this to be the
> >case until I read a water report.
> >  
> >
> I found local water report for 2003 and had kept it
> for 2002.  Not an 
> easily read report for lay people, IMHO.
> It uses separate 85% surface water figures and 15%
> ground water figures, 
> so you have to run the totals yourself.
> With those percentages of the surface/ground mix
> (which could vary 
> across the area by source), on average:
> 
> 2003 Na: surface 5.4 ppm ave., ground water 25 ppm
> ave. =   8.3 ppm 
> total ave.
> 2002 Na: surface 4.8 ppm ave., ground water 30 ppm
> ave. =  8.6 ppm total 
> ave.
> 
> 2003 Ca: surface 13 ppm ave., ground water 23 ppm
> ave. = 14.5  ppm total
> 2002 Ca: surface 14 ppm ave., ground water 33 ppm
> ave. =  16.9 ppm total
> 
> 2003 Mg: surface 3.8 ppm ave., ground water 14 ppm
> ave. = 5.3 ppm total
> 2002 Mg: surface 3.6 ppm ave., ground water 20 ppm
> ave. = 6.1 ppm total
> 
> (which gives an interesting ratio, Ca:Mg
> surface=3.4, 3.9 Ca:Mg ground 
> =  1.6, 1.7, and tap average Ca:Mg = 2.7, 2.8,
> in other words, a ratio of Ca: Mg = 10:3  to 10:4 in
> my tapwater. Quite 
> a ways off from 3:1, or 4:1!  Sounds like the Mg in
> the makeup water 
> does need to go way up!)
> 
> 2003 Hardness:  surface ranges from 27-74, ave. 44
> ppm, ground water 
> ranges 70-156, ave. 112 ppm.
> Or 54.2 ppm total ave.or (dividing by conversion
> ppm/dGH=17.9) 3 dGH, 
> which is about what I measure out of my tap.
> 
> 2002 Hardness:  surface ranges from 27-58, ave. 42
> ppm, ground water 
> ranges 112-278, ave. 164 ppm..
> Or 60.3 ppm total ave. or (dividing by conversion
> ppm/dGH=17.9) 3.4 dGH.
> 
> 2003 nitrate, "None detected" surface waters,  5.2 
> ppm ground water =  
> .8 ppm total ave.
> 2002 nitrate, .38 ppm surface waters,  7.3 ppm
> ground water = 1.4 ppm. 
> total ave.
> 
> When I did nitrate test on tap, I got zip-1 ppm,
> below threshold on the 
> Tetra test kit.
> So I probably ought to count that about 1 ppm of my
> tank's nitrate is 
> right from the tap, particularly in summer!
> ie., don't use the wells around here, and count on
> higher nitrate 
> numbers in a drought year!
> 
> >I think you should just raise the GH to 4-6 by
> using
> >equilibrium and just forget about it. It is one
> thing
> >less to worrry about while you are trying to dial
> in
> >your traces.
> >
> >Currently your CO2 according to the chart @pH 7.4,
> dKH
> >4, dGH 6 is only 4.7. This is still your main
> problem
> >
> I've been dialing the CO2 and bringing down the pH
> very gradually, while adding more lime and soda at
> water change.  At last testing, I had kH 4, GH6,
> with pH at 7.4.  I want to bring that down to
> 6.8-6.4.
> 
=== message truncated ===

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