Approximating Seachem Iron with chelated Iron

AquaticJim

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Aug 2, 2007
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Does anyone know a mix that I can make up using chelated iron at 13% to approximate Seachems Iron product?
 

scottward

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Oct 26, 2007
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Jim,

I've been using 1 tablespoon of 13% EDTA iron (can buy this stuff dirt cheap in Big W) in 500mls water, I dose 30mls 3x per week.

I think this is a pretty good approximation, based on some very detailed discussion and calcuations I did earlier in the year with the guru team.

Obviously I could suddenly stop dosing this to see if anything 'bad' happens, but, given the number of variables in this hobby it would be hard to say without some very good controls whether I have an iron deficiency or some other factor has crept in.

FWIW, I made up a 2 tablespoons per 500mls solution and dosed that for a month or so, tank didn't seem to do any better or worse so I went back to 1 tablespoon.

Maybe I don't need to dose it at all, the only reason I did was because I have lots of echinodorous in my tank and wanted to rule out iron by ensuring I'm always adding plenty.

So peace of mind really.

Did I mention that this hobby is easily the most challenging of all my many hobbies??? :D

Scott.
 

Biollante

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Approximately An “Approximation,” Which Government Agency?


Hi Jim,


I am no Guru but…:eek:



Scott’s “approximation” is approximately [SUP]1[/SUP]⁄[SUB]3 [/SUB] Seachem’s solution strength.:rolleyes: The Seachem Iron is a 1% solution, or 10,000-ppm.:)


To approximate Seachem with 13% chelated iron, mix approximately 38.5-grams (approximating 8 ¾ teaspoon) 13% Fe[SUP]2+[/SUP] into approximately 450-ml of distilled water, then add enough distilled water (approximately 12.5-ml) to make approximately 500-ml .



Biollante
 

LoudCreature

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Biollante;74009 said:

Hi Jim,


I am no Guru but…:eek:



Scott’s “approximation” is approximately [SUP]1[/SUP]⁄[SUB]3 [/SUB] Seachem’s solution strength.:rolleyes: The Seachem Iron is a 1% solution, or 10,000-ppm.:)


To approximate Seachem with 13% chelated iron, mix approximately 38.5-grams (approximating 8 ¾ teaspoon) 13% Fe[SUP]2+[/SUP] into approximately 450-ml of distilled water, then add enough distilled water (approximately 12.5-ml) to make approximately 500-ml .



Biollante

Seems about right

Wet's calculator thingy does not do 13%

I may use 13% since that is a lot less than what 10% is

LC

LC
 

scottward

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Oct 26, 2007
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My apologies - in an earlier thread created by me I was trying to approximate Seachem Flourish (i.e. traces) using Rexolin APN. Because this already adds a certain amount of iron, I was making up the balance using 13% EDTA in a seperate bottle. For some reason I though I was targetting Seachem Iron in terms of concentration, but actually I wasn't, I was targetting a specific in-tank iron level. So I was using my Rexolin dose + 2 tablespoons of EDTA iron in 500mls of water + my amount per dosage/frequency of dosage to get there....

Jim, any idea what your iron target will be?

Scott.
 

AquaticJim

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Aug 2, 2007
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I'm so stoked.....I asked this question over 4 years ago and I finally got an answer!!!!!

:) :) :)
 

AquaticJim

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Aug 2, 2007
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I have two more questions that relate to iron :)

(hopefully answered before 2015 :) )


1. Why does Seachem Iron cloud my water around 15 minutes after being added and the 13% chelated mix doesn't?

2. Is there a 'best' time in regards to the photoperiod of when to add iron? Before lights on, after lights on, end of the photoperiod?
 

Biollante

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Party Like Its 2015!


Hi Jim,

Thank Scott, his post is what provoked my response:), I never looked at the date… Had you not mentioned it:rolleyes:, I still wouldn’t have known:eek:, so much for my observational skills!:p


I am quite sure that Seachem Iron clouds your water for a bit while the 13% chelated mix does not, because Seachem’s chelating agent is, basically, sugar while the 13% stuff is either EDTA or DTPA, acids that bind iron better.:)


Perhaps toss a similar amount of table sugar or corn syrup in and see if it looks the same. If it does it is most likely the sugar (the bugs will enjoy it anyway). If it does not appear the same, odds are it is the iron precipitating.:confused::eek:


If I recall this correctly gluconate actually complexes the iron (as opposed to EDTA and DTPA that chelate or bind the metal) as a result of the weaker bonds the iron though, in a more plant friendly form, the iron “falls” out much sooner. I will have to look this up later.


  • It is also possible that higher levels of potassium add to the tendency of the iron to fall out of the gluconate bond.
  • Again, I think I am forgetting something and I will have to look it up.:eek:

I would assume that early in the day iron dosing would give the best odds of the iron, especially the weaker bonded complexed iron being used.


Biollante

 
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Wet

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LoudCreature!

If you want it, the calculator does do 13% (EDTA) and 12.5% (Gluconnate) Fe.

Rawr!
 

Biollante

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Complexation, Chelation, Who Can Keep Track


Hi Jim,

You are welcome.:cool:



My “complex versus chelation” is weak to say the least:eek:, but the general idea is there. :)


The complexation idea that the Fe gluconate bonds are much weaker than those formed by EDTA, which are weaker than those formed by DTPA.


All of this seems to be a function of the “stability constant,” which is an equilibrium constant that governs formations of complex solutions, a measure of the of the interaction strength between the materials that form the complex. We are mainly with complexes formed by the interaction of a metal ion with a ligand (as opposed to supramolecular complexes). (Math below)

Glucose oxidation produces gluconic acid, gluconate, is the salt. In nature Gluconic acid, results from fungal oxidation.


When I used Seachem Iron, I came to suspect the bugs got more out of it than the plants, it is cheaper to toss a teaspoon of sugar every now-and-then, rather than buy expensive Fe Gluconate, which I rather think has a life of a couple of minutes in the average aquarium. I your case it seemed to be seconds, rather than minutes.:p


Stability%2520ConstantAqueousSolution.jpg



Biollante

 

LoudCreature

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Oct 17, 2009
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Wet;74133 said:
LoudCreature!
If you want it, the calculator does do 13% (EDTA) and 12.5% (Gluconnate) Fe.
Rawr!

Thank you, once again you showed me the way!

if i'd listen to Biollante I would of used way too much!:p;)

Seriously, you should label that stuff

and I know this is a "guy thing"--- you really need a user friendly front end

someday you may find girls aren't icky:eek: and may want them to come out and play...

no boys will own up, bet a couple of them have a hard time with it---just saying:)


Wet13EDTA.jpg


thanks it is great calculator and lots of fun
LC
 

Left C

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Wet;74133 said:
LoudCreature!

If you want it, the calculator does do 13% (EDTA) and 12.5% (Gluconnate) Fe.

Rawr!
You don't have any amounts showing what percentage of Fe is used for EDTA Fe and Fe Gluconate in the calculator. It just lists the names of these two compounds. Must be an overlooked typo. :)

Like LoudCreature says: "label it."
 
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