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Which iron chelate should I use?

mrtank50

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6 Jan 2021
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Türkiye
Hello friends. Which iron chelate should I use?
I have a tank with soft water.

I have csm+b but I can't get full efficiency because the iron form is edta.

Would it be more efficient to mix csm+b with ferrous gluconate or just use ferrous gluconate?

Or is there a brand of fertilizer you recommend?
Seachem iron vs.




Aquarium features:

KH-0/1
GH-5
PH-5.5/6
TDS-100/120
LITER-150
LIGHT-39*6
Soil : ADA AMAZONIA
FERTILIZER- Eİ NPK
 
Gluconate breaks down really fast and I don’t think it’s absorbed as well in hard water either. If your water is in the higher pH range you’ll want to use DTPA or EDDHA. I’d try the DTPA first.
 

Hi Mr Tank,

You are able to pump 150ppm CO2 in your tank and your PH is 5.5,

There shouldn't be any concern about which Chelate to use - just dose Fe while you are pumping CO2.

Look forward to updated photos of your tank, hows the Pantanal and Senegalensis?

By the way, the recommendation in UKAPS is that if you have many questions, it may be better to have a journal where your questions and problems can be addressed in a holistic manner, instead of posting different threads. For example, in your recent CO2 thread (last week) you said you had Kh4, Gh6, but here you say Kh1 Gh5.... so we don't know if you have multiple tanks and which one you are asking for help on.
 
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You are able to pump 150ppm CO2 in your tank and your PH is 5.5,
I think the infamous KH/PH/CO2 chart is the source of this belief. I don't believe for a second he has 150ppm of CO2 in his tank.

Also that tank you are referring doesn't seem to be the same tank that is being referred in this thread unless he made some changes and parameters changed.
 
Thanks guys for your valuable reply.

I have about 9 tanks.

My tank with 150 ppm co2 is a different tank.

I'm thinking of starting a thread with that tank soon.
 
Hello friends. Which iron chelate should I use?
I have a tank with soft water.

I have csm+b but I can't get full efficiency because the iron form is edta.

Would it be more efficient to mix csm+b with ferrous gluconate or just use ferrous gluconate?

PH-5.5/6
Hi @mrtank50, With softer water and a pH in that range your fine with EDTA chelates.

Here is a chart showing availability of Fe with various chelates as a function of pH:

1650557334273.png


As you can see at a pH of 5.5-6.0 there are no short term precipitation that would render it unavailable to the plants (we are talking several weeks here). Back when I was running my tanks in the 7.2-7.4 pH range I would supplement with a mid-week dose of Fe Gluconate (Seachem Iron), now that my pH is down in the lower 6 range there is no need for that.

Hope this helps!

Cheers,
Michael
 
well, I used to dose 1ppm Fe weekly from EDTA but still had iron deficiency. this tank was very softwater, ~5gh, 0kh ph never measured but had active substrate so, the ph should be 5 or so.
once I changed that to DTPA at 0.1ppm Fe weekly (same gh) it was just fine, plant tips grew nice and greened up well. 0.05ppm weekly was too low, 0.075ppm was borderline.
 
well, I used to dose 1ppm Fe weekly from EDTA but still had iron deficiency. this tank was very softwater, ~5gh, 0kh ph never measured but had active substrate so, the ph should be 5 or so.
once I changed that to DTPA at 0.1ppm Fe weekly (same gh) it was just fine, plant tips grew nice and greened up well. 0.05ppm weekly was too low, 0.075ppm was borderline.
Hi @plantnoobdude, Very interesting observation. I wonder if that could have been induced by something else in combination. In any event, I suppose this could also be plant species related.

Cheers,
Michael
 
Hi @plantnoobdude, Very interesting observation. I wonder if that could have been induced by something else in combination. In any event, I suppose this could also be plant species related.

Cheers,
Michael
well, apart from that the main change was a difference in Fe:Mn ratio. Mn was still much less than what I was dosing with my premade mix.
 
before I was dosing 1ppm fe with 0.2-0.3ppm Mn if I remember correctly.
now I am dosing 0.1ppm Fe with 0.067ppm Mn. while the total value is still much less, the ratio is different.
I believe certain plants might have a harder time absorbing Fe EDTA vs. DTPA, but it is also depending on other nutrients as you have experienced. The pH relationship is definitely a factor, but only part of the story as we know. Personally, I never had Fe deficiency in the past with slow growing easy plants in a low-tech environment - regardless of EDTA Fe use and pH level - I was only hedging my bets with Fe Gluconate before encountering any signs of deficiency in the first place.

Cheers,
Michael
 
This is a bit of an older thread but i found it trying to find the info i wanted. I"m buying CSM+B and trying to decide at what point i need fe2 additive (csm+b contains fe3); the cross over seems around ph 6.8-7.5 my question is does someone know a narrower range for the ph - i.e, with 6.8 should i be adding some fe2 or is that sufficient for fe3 only - how about 6.5 ? To be honest I'm not sure how soft my water will be - the tap is kh 3/ph 7 but i will mixing it with some ro (this is for the 450 i'm setting up in april) i think i will try for 1 part tap 2 part ro so maybe kh will be near 1 but not sure where the ph will settle.
 
This is a bit of an older thread but i found it trying to find the info i wanted. I"m buying CSM+B and trying to decide at what point i need fe2 additive (csm+b contains fe3); the cross over seems around ph 6.8-7.5 my question is does someone know a narrower range for the ph
Are you going to use Plantex CSM+B ? (EDTA). I am using it in one of my tanks running at pH around 6.3. As you can see in the chart above (post #8) EDTA falls off fairly rapidly above pH 7. I would say if you are below 6.8 I wouldn't worry about it. Not sure if that helps answer your question. If your KH is low (< ~2 ... which it sounds like yours will be) its easy to acidify the water with some botanicals.

Cheers,
Michael
 
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I believe certain plants might have a harder time absorbing Fe EDTA vs. DTPA,
I will not pretend this issue is very clear to me. However...
Recently, I've been slowly re-reading Marschner. I've recalled following scheme:
1678310443151.png
Also, other sources say that plants uptake iron in ionic form. Which suggests that EDTA and similar chelates serve to keep iron in the solution, but plants take it up at the moment when the chelate bond is broken and iron is present in ionic form. Then the plant itself creates its own iron chelate, reduces Fe3+ into Fe2+ and takes it up. Then, in xylem, iron is mostly present as Fe3+-citrate (which is also a chelate bond).

Generally, I find many complaints on iron accessibility difficult to understand. At pH value clearly below 7 there should be little problem. Situation may be complicated by:
(1) Bicarbonates. When injecting CO2, you can make the water acidic while bicarbonate content (KH) remains quite high.
(2) Phosphates. Phosphates in themselves are quite harmless as plants can regulate well phosphorus uptake. However, phosphates form precipitate with iron - FePO4. If your water is rich in phosphates, much of iron is lost.
(3) Precipitated iron, be it oxides, hydroxides, carbonates, phosphates, silicates a.o. are not lost forever if they fall down to the substrate. Lowered redox and bacteria can make such iron available again. However, if you filter water vigorously, most of these precipitates end up in filters and there the chance of getting dissolved again is probably very low. You've certainly encountered your filter media brown coloured. That's trivalent iron in various forms.
 
Generally, I find many complaints on iron accessibility difficult to understand. At pH value clearly below 7 there should be little problem. Situation may be complicated by:
(1) Bicarbonates. When injecting CO2, you can make the water acidic while bicarbonate content (KH) remains quite high.
(2) Phosphates. Phosphates in themselves are quite harmless as plants can regulate well phosphorus uptake. However, phosphates form precipitate with iron - FePO4. If your water is rich in phosphates, much of iron is lost.

I think you hit it right on the nail there @_Maq_ I've come to believe (and it is believe, because I don't know nearly enough about bio chemistry to do otherwise)... that low pH AND low phosphate is the great enabler for Iron uptake. Hence the reason I can get away with 0.032 ppm/wk in my lean tank without my plants suffering from any signs of Fe deficiency.

Cheers,
Michael
 
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Are you going to use Plantex CSM+B ? (EDTA). I am using it in one of my tanks running at pH around 6.3. As you can see in the chart above (post #8) EDTA falls off fairly rapidly above pH 7. I would say if you are below 6.8 I wouldn't worry about it. Not sure if that helps answer your question. If your KH is low (< ~2 ... which it sounds like yours will be) its easy to acidify the water with some botanicals.

Cheers,
Michael
I will be using nilogc CSM+B (which is very similar) and i believe my ph will settle around 6.8 but it will be another 45 days before i have the aquariums setup.
 
I will not pretend this issue is very clear to me. However...
Recently, I've been slowly re-reading Marschner. I've recalled following scheme:
View attachment 202183
Also, other sources say that plants uptake iron in ionic form. Which suggests that EDTA and similar chelates serve to keep iron in the solution, but plants take it up at the moment when the chelate bond is broken and iron is present in ionic form. Then the plant itself creates its own iron chelate, reduces Fe3+ into Fe2+ and takes it up. Then, in xylem, iron is mostly present as Fe3+-citrate (which is also a chelate bond).

Generally, I find many complaints on iron accessibility difficult to understand. At pH value clearly below 7 there should be little problem. Situation may be complicated by:
(1) Bicarbonates. When injecting CO2, you can make the water acidic while bicarbonate content (KH) remains quite high.
(2) Phosphates. Phosphates in themselves are quite harmless as plants can regulate well phosphorus uptake. However, phosphates form precipitate with iron - FePO4. If your water is rich in phosphates, much of iron is lost.
(3) Precipitated iron, be it oxides, hydroxides, carbonates, phosphates, silicates a.o. are not lost forever if they fall down to the substrate. Lowered redox and bacteria can make such iron available again. However, if you filter water vigorously, most of these precipitates end up in filters and there the chance of getting dissolved again is probably very low. You've certainly encountered your filter media brown coloured. That's trivalent iron in various forms.
So this means when I dose phosphate (kh2po4/kno3); i'm actually countering the iron in csm+B. Maybe i should go light on the first two ?
 
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