Andy Pierce
Member
They just haven't reported it. 😉
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No chelator in soft water ?
- Thread starter eminor
- Start date
Hi all,
cheers Darrel
Because UKAPS is the <"gift that keeps giving">, here you are - <"Frogbit taken a turn">. This is from @jameson_uk
cheers Darrel
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John q
Member
I stand corrected.
ExcitableBoy
Member
Why should they behave similarly? I think you are looking at it from the wrong point of view. It's not about what kind of iron is released once the bond between it and the chelating agent is broken, otherwise we should think that every chelating agent which releases Fe 2+ or 3+ is the same. It's about how long Fe will remain in solution thanks to the bond with "something".
The bond between Fe and Gluconate and the one between Fe and SO4 look quite different. Thanks to the resonance of gluconate the iron atom looks more covered by negative charges, thus Fe Gluconate seems more "stable" (I mean, not as stable as edta or dtpa of course).
Anyway iron gluconate is probably more expensive than iron edta/dtpa. I didn't think about this, I just wanted to suggest to use something that is known to work.
You can try FeSO4, though I think you are just going to fill the substrate with Fe2O3, but I am not 100% sure.
You could also buy EDTA and chelate FeSO4. Honestly I know nothing about this, it could be not so convenient and more expensive than buying directly iron edta. Maybe Darrel @dw1305 did it if I remember right?
Andy Pierce
Member
Well... to be fair, even though I'm using Fe-EDTA in my pH 9 aquarium, I dose once weekly to a concentration of 0.2 ppm and the stock solution is kept well acidified with 5 ml of 5% vinegar per 500 ml which would be at a pH of around 3.4. Apparently that is "good enough". The lighting level is also pretty low (to prevent algae) where iron chelators are known to be photodegradable.
Hi all,
Cheers Darrel
I think is the important bit, you need a continual trickle of Fe++(+) ions to become plant available. The problem is that the plant can't store iron for a rainy day.
I did, you can make the other chelates by starting with di-sodium EDTA. Monovalent captions are the least strongly bound, so a solution of iron sulphate (FeSO4.7H2O) and di-sodium EDTA will become a solution of FeNaEDTA, I'll need to find the exact recipe.
Cheers Darrel
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Valid points, but once either one is added to the aquarium, both are highly prone to prectipations and oxidization, Even though Fe gluconate might look more superior due to its ability to form chelation/complexes. This bond is still extremely weak and can be easily overcome by oxygen, prectipations etc.
One of the recipe is here but it is still cheaper to just buy an EDTA Fe. I believe @eminor was looking into this option. His FeSO4 approach should be similar to @_Maq_ using FeCl and Maq can probably shine more light on this topic.
_Maq_
Member
I've tried using both.
When you put FeSO4 in contact with (oxygenated) water, a precipitate of Fe-something (supposedly Fe(OH)3) appears instantly. It's not a powder but "something brown" (emulsion) floating in the water column. We know it from nature as a typical "iron water".
When you dilute FeCl3, nothing like that happens. Frankly, I don't quite know why. The difference is that here the iron is already trivalent (in contrast to bivalent, reduced iron in FeSO4), so it doesn't oxidize. Stock solution of FeCl3 is stable.
FeCl3 is my iron fertilizer of choice.
I've experimented with Fe-citrate, too. The nice thing about Fe-citrate is that citrate forms various complexes with iron - both bivalent and trivalent - at the same time. Add to that citrate is a natural chelator, unlike EDTA & co. For me, in my conditions, it does not work any better than FeCl3, and the stock solution stability is somehow limited; I suspect bacteria get present and transform the chelate in their own way.
I've also made an interesting experience with Ludwigia glandulosa in pH between 7 and 8. It suffered iron deficiency, and I've attempted to help with FeCl3, Fe-citrate, and Fe-EDTA, one after another. Nothing worked, while Ammania crassicaulis remained healthy (even with unchelated FeCl3). So, there was no absolute lack of iron there, but some species simply could not take up or utilize iron no matter what I've tried. (Unfortunately, I don't possess any "stronger" iron chelates.)
All that I've said is subject to the real masters of our tanks - the microbes.
