Re: [AGA-Member] Magnesium nutrient issues

[Heather J Gladney <hgladney@comcast.net>]

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.

Currently

> You need to push your CO2 up to 20-25 and then you
> will likely have to readjust your traces as consuption
> goes up. 
>
> I also use Fe (.2ppm) as the proxy as recommended by
> Tom Barr, Roger Miller and others to set my trace
> levels. You are going to get your traces in line AFTER
> you get the CO2 issue resolved. Once this is done then
> you can start fine tuning your dosing and water in
> relation to the amount of light and depth of your
> tank.
>
> You also have a lot of light at nearly 4 watts/gallon.
> You may want to dial it back to a little less than 3
> watts/gal until you get your tank balanced.
I have shortened the photoperiod a bit, down to just under 10 hours.  
I'm already using a midday break to let all the bulbs cool when it's 
hot.  Not a problemn now, but it will be in summer.
If  I wanted to tone down the wattage as well as the heat, I could run 
each bulb on its own timer in sequence, so at any given time there's one 
out of 4 bulbs turned off for a cooling break.  This might cost 
longevity for such frequent on/off all the time, but it might also 
extend the bulb life because they're not cooking the cover glass hot 
enough to fry eggs on!

> Remember
> that the more light and CO2 you have the more traces
> you will need to be available to the plants so the
> less margin you have for error in your dosing.
Thanks very much for your help!

> Regards
> Larry Lampert
> Dallas, TX
>
>
> --- Cheryl Rogers <cheryl@wilstream.com> wrote:
>
>  
>
> > No one ever answered this. What a drag. I was
> > looking forward to it.
> >
> > Cheryl
> >
> > Heather J Gladney wrote:
> >    
> >
> > > My 90 gallon tank (actual gallons about 76) has
> > >      
> > lots of long stringy 
> >    
> >
> > > algae,BBA, and one large old SAE.
> > > As it's a tall hexlike diamond shape, I've got
> > >      
> > power compacts on it, 2 X 
> >    
> >
> > > 55 watt and 2 X 96 watts, for total 302 watts, or
> > >      
> > not quite 4 
> >    
> >
> > > watts/actual gallons.
> > > It generally has 0 nitrite and about 12 ppm
> > >      
> > nitrate, probably due to 
> >    
> >
> > > fish + food.
> > > I'm not certain how many inches of fish it has
> > >      
> > because the Corydorus 
> >    
> >
> > > catfish breed in there, and I keep finding new
> > >      
> > babies.
> >    
> >
> > > It used to have CO2 injection issues, and CO2 was
> > >      
> > off completely for 
> >    
> >
> > > about 2 weeks.
> > > I'm trying for a community tank balance, as I'm
> > >      
> > keeping both Cardinal 
> >    
> >
> > > tetras (soft acid water) and Cryptocorynes that
> > >      
> > like hard alkaline water 
> >    
> >
> > > (bad owner!!).  In fact, the C. balansae grew
> > >      
> > better when my CO2 line 
> >    
> >
> > > was down.
> > > I think I finally got the CO2 supply fixed this
> > >      
> > weekend, thanks to 
> >    
> >
> > > helpful advice from folks here.
> > >
> > > Now I'm thinking about the nutrient dosing to work
> > >      
> > on that hair algae 
> >    
> >
> > > and BBA.
> > > I'm coming up with some odd numbers on Epsom salts
> > >      
> > from the ratios that 
> >    
> >
> > > people suggest.
> > >
> > > Normally, with CO2 injection, the tank was at pH
> > >      
> > 6.8-7.0, dKH 5-6, dGH 7-8.
> >    
> >
> > > Without the CO2, the tank went up to pH 7.4 - 7.8,
> > >      
> > same dKH and GH.
> >    
> >
> > > Tap has KH 2, GH 3, so some months ago I started
> > >      
> > adding powdered 
> >    
> >
> > > dolomitic limestone (from Greg Watson) and baking
> > >      
> > soda to bring makeup 
> >    
> >
> > > water one point each to dKH 3, dGH 4.  This isn't
> > >      
> > as high as some 
> >    
> >
> > > 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.
> >    
> >
> > > Which says there's hardly any Mg in there.
> > >
> > > Awhile back someone reminded me of Tom Barr's
> > >      
> > advice, and suggested 
> >    
> >
> > > bringing up dKH to 4-5 and add some soda for
> > >      
> > better pH buffering.  
> >    
> >
> > > Because of that, and to better match the tank's pH
> > >      
> > without any CO2 
> >    
> >
> > > injection, on my latest 30% water change, I
> > >      
> > doubled the limestone and 
> >    
> >
> > > soda amounts as I got the CO2 injection going
> > >      
> > again.
> >    
> >
> > > Now, with CO3 injection started, the tank tests at
> > >      
> > pH 7.4, dKH 4, dGH 6.
> >    
> >
> > > The difference is 2 points, just what you'd expect
> > >      
> > from doubling my 
> >    
> >
> > > previous soda amount in the makeup water.
> > > I also added fertilizers that include macros, Mg,
> > >      
> > Fe, traces, and so on, 
> >    
> >
> > > but clearly not enough Mg to affect the dGH-dKH
> > >      
> > hardness difference very 
> >    
> >
> > > much.
> > > As I adjust the CO2 injection, I'll bring that pH
> > >      
> > down gradually to 
> >    
> >
> > > 6.8-6.9 to get better CO2 percentage.
> > > But perhaps I ought to increase my limestone and
> > >      
> > Mg amounts too.
> >    
> >
> > > That made me start to recalculate my dosing drops.
> > >
> > > Please correct me if I'm wrong, but could I
> > >      
> > increase dGH by skipping the 
> >    
> >
> > > soda and adding Epsom salts for Mg instead?  This
> > >      
> > should increase 
> >    
> >
> > > general hardness for buffering the pH, and the
> > >      
> > plants would like Mg 
> >    
> >
> > > better anyway.
> > > I thought of this because I saw comments noting
> > >      
> > that the ratio of lime 
> >    
> >
> > > to Epsom salts should be roughly 4:1, or:
> > > CA(CO3) : MgSO4, should be 4:1, which ties my dKH
> > >      
> > to how much Epsom 
> >    
> >
> > > salts I add.
> > >
> > > Working from "the ideal Mg amount":
> > > My hardness test kit instructions show 17.9 ppm =
> > >      
> > 1 degree for both dKH 
> >    
> >
> > > and dGH.
> > > Chuck Gadd's nutrient calculator page suggests the
> > >      
> > guideline of 5-10 ppm 
> >    
> >
> > > of Mg, but other comments suggest it can be more.
> > > If I maintain the ideal Mg of 5-10ppm, that 4:1
> > >      
> > ratio gives 20 - 50 ppm 
> >    
> >
> > > CA, or dKH =1.1 - 2.8, which I thought was pretty
> > >      
> > soft water.  A lot 
> >    
> >
> > > softer than what I've got going!
> > > But list comments note that many plants like hard
> > >      
> > water, that it can go 
> >    
> >
> > > higher.
> > >
> > > Working from the hardness I've already got:
> > > With current dKH of 5 - 6, or 89.5 -107.4 ppm Ca,
> > >      
> > a 4:1 ratio that gives 
> >    
> >
> > > 22.38 - 26.85 ppm Mg.
> > > That is double the high recommendation.  Also, it
> > >      
> > requires adding 4 - 
> >    
> >
> > > 4.5 tablespoons of Epsom salts dry directly to the
> > >      
> > tank.
> >    
> >
> > > This sounds like an awful lot!
> > > It also adds that same amount of sulfur, and I
> > >      
> > planned to add sulfur 
> >    
> >
> > > elsewhere by using potassium sulfate (K2SO4) as a
> > >      
> > K source.
> >    
> >
> > > (I don't want to use KNO3, because the N is plenty
> > >      
> > high in this tank 
> >    
> >
> > > right now--I hope that it'll go down if I can get
> > >      
> > the plants growing 
> >    
> >
> > > better..)
> > > Do we have any guidelines on how much sulfur is
> > >      
> > too much?
> >    
> >
> > > Also, how much change in dGH does that much Mg do?
> > >      
> > Don't think I'd need 
> >    
> >
> > > to add any baking soda, though!
> > >
> > > Whic leads down to the final question, would it be
> > >      
> > okay to push up the 
> >    
> >
> > > Mg to keep the ratio with Ca intact, or should I
> > >      
> > leave it at Chuck's 
> >    
> >
> > > 5-10 ppm and a lower calcium amount and lower dKH,
> > >      
> > which I suspect the 
> >    
> >
> > > fish would like a little better?
> > >
> > >
> > >
> > >      
> > --
> > Cheryl Rogers, Membership
> > Aquatic Gardeners Association
> > http://www.aquatic-gardeners.org
> > _______________________________________________
> > AGA-Member mailing list
> > AGA-Member@thekrib.com
> > http://lists.thekrib.com/mailman/listinfo/aga-member
> >
> >    
>
> _______________________________________________
> AGA-Member mailing list
> AGA-Member@thekrib.com
> http://lists.thekrib.com/mailman/listinfo/aga-member
>
>
>  



--
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.300 / Virus Database: 266.5.0 - Release Date: 2/25/05

_______________________________________________
AGA-Member mailing list
AGA-Member@thekrib.com
http://lists.thekrib.com/mailman/listinfo/aga-member