FE EDDHA

dw1305

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Hi all,
That would be very useful.
The original papers are <"Ullrich CI, Novacky AJ (1990) Extra- and intracellular pH and membrane potential changes induced by K+, Cl−, H2PO4 -, and NO 3 uptake and fusicoccin in root hairs of Limnobium stoloniferum."> Plant Physiol 94:1561–1567 & <"Are Redox Reactions Involved in Regulation of K+ Channels in the Plasma Membrane of Limnobium stoloniferum Root Hairs"> A Grabov, M Bottger - Plant Physiology, 1994.

Neither of those specifically talks about ferric reductase activity in the rhizosphere, but they go through the physiology of root hair ion uptake. I'm not a plant physiologist and I had to ask some-one who is to "help me with the long words".

This one should be available to everybody: <"Grillet L & Schmidt W (2017), The multiple facets of root iron reduction, Journal of Experimental Botany 68:18, 5021–5027"> and is a bit more accessible.

This is below pH7



and this one is above pH7



It looks like this is a pretty universal mechanism in all plants (from the Bryophytes upwards), other than grasses.

cheers Darrel
 

dw1305

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Hi all,
Some people tell me that having a fish tank is very restful, I wonder
That is sort of why I've pushed the <"Duckweed Index">. It has a basis in science, but all the interesting/scary* bits are hidden under the hood.

Personally I would like to be able to quantify everything about the way a tank works, how plants grow, the interaction between DOC and nutrient availability etc. but it isn't a realistic aspiration and I'm a pretty shoddy aquarium keeper, so I need to cut to the chase, which for me is:
Rather than the regular addition of nutrients, I use <"a different approach">. I have a floating plant (usually <"Limnobium laevigatum">) and ,<"heavy planting"> of <"easy" plants"> in the tanks. I just watch the <"growth and leaf colour of the floating plant"> (so not CO2, or light, limited), all the time the leaves are green and the plant growing (how ever slowly) I don't add any nutrients (other than whatever arrives via water changes).

When plant growth (or leaf colour) deteriorates I add some nutrients, once growth has resumed it is back to observing and waiting.
*delete as appropriate.

cheers Darrel
 

Oldguy

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all the interesting/scary* bits
I must admit I like to know how stuff works, not a rivet counter, but the more technical side of 'having a tank' maintains a connection with a past life. Seldom test the water, as you say if the fish and plants are doing well then all is well. However a few toys in the cupboard are a good investment when you are a stand alone.

Still saddened by people who just do not see plants.
 

dw1305

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Hi all,
Diatom algae :thumbup: watched a good program on it on netflix 'One Strange Rock'
I haven't seen that one. The estimate is that over half the Earth's oxygen is attributable to Marine Algae, and Diatoms will make up a good proportion of that. The figure quoted is 40% for Diatoms, but the estimates for the proportion of the Earth's oxygen from marine phytoplankton is between 55% - 80%, so that doesn't really help very much.

cheers Darrel
 

FishWorks

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Happy Easter Everyone!

Just a brief intro, I have a new thread which is about FE DTPA but was invited here since its a chelator topic aswell.
From my general readings, DTPA chelator is stable up to 7 PH, above 7 it starts degrading and chemical half-life happens at 7.5 (50% concentration point).
Link Below (go all the way down to the section about half life):
https://www.ukaps.org/forum/threads...water-supply-with-an-allinone-solution.52972/

So I think DTPA is a great chelator if you can bring your PH below 7.5 which is an easily done with CO2 injection.
My Hi-Light Tank for example, my water parameters 8.1 PH, 4 KH, 4 GH. After CO2 injection, I come down to 7.1 PH and I have about 90% FE DTPA remaining. Thinking about those numbers, then up to 8.5 PH, FE DTPA is still pretty good. Craig comes down from 8.1 PH to 7.3, which is why Zeus is telling Craig:
You could go down the Fe DTPA route -
Fe chelated by DTPA: min 10.5%
Practical pH stability range: 4 – 7.5 (in aqueous solution).
So as long as you can get below 7.5 PH (like say 7.4), then dosing FE DTPA (hopefully 1-2 hours into the photoperiod), you still have about 60% FE DTPA which is a good amount. You don't need a whole lot, that 60% for a few hours is enough.
I can quote Darrel and Ceg4048 on this:
The thing about Iron though, is that the plants don't really need a lot and in a high tech tank, within an hour or so the plants has as much Fe as it needs, so it really is not a big problem. If you lost 50% of the Iron then just dose more often and it will get there
Yes I'd just add a pinch, and when you can't see any pink tinge add another pinch, plants don't need a lot of iron. The problem with very hard water is that there aren't any iron ions available, all the iron is combined into insoluble compounds and none of it is plant available.

So I get down to what is bothering me, If ones goal were to dose 1ppm FE DTPA weekly using standard EI on Tuesday, Thursday and Saturday (.33ppm each time), would anyone agree with me that a single dose on each of these days is enough?
or would you prefer to dose twice in 2 hour intervals? or dose three times in 2 hour intervals?
Perhaps you would prefer to dose FE DTPA at 2ppm or 3ppm per week?

so this makes me think should I dose my Micro mix with FeDTPA in it in one dump or multiple ? multiple for the photoperiod seems to be the obvious answer to me and easy to do with PLC so three equal doses two hours apart from lights on done ;)
I can see that Zeus, like me, is also wondering about the dosing method above ;). Because of EI method, we can dose in excess and not care about Algae, provided you dont go ridiculous amounts (like say a sensible 3ppm FE DTPA versus a ridiculous 50ppm FE DTPA). So if we wanted healthy growth, we could dose thrice per day on Tuesday, Thursday and Saturday (Each dose .33ppm, that will be 9 doses totalling approximately 3ppm)? Would this be okay for livestock like Cardinal Tetra?

Cheers,
-Harry
 

Zeus.

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I just had a look on rotala butterfly and a quick Google and both surgest 5ppm of Fe is safe for freshwater livestock, but no expert OFC.
But your surgestion to allow for the the dissociation constant changing with the different pHs so if it's only 50% dissolved dosing double the dose will make the initial dose closer to the target, however as the Fe ions are mopped up by the plants as they need/use them this will reduce the total Fe ions in solution and more of the percipited Fe should then dissolve into solution to maintain equilibrium so it should ( I think ) regulate itself to some extent as the plants uptake Fe so a double dose may not be needed IMO.
But having said that from what I have read the chemistry of the availibity/interactions of ions with very hard water gets more complex, hence the reason why you tend to see/read about tanks with soft or RO reminerilsed water doing so well.
 
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I'm a week into dosing a tea spoon tip of Fe eddha using the slight pink tint method and haven't encountered any problems with live stock. The tint does dissapear rather quickly in 24hrs. I haven't has enough time to comment on a change will need a few more weeks. I haven't used equations or ppm, grams etc as I'm very poor at maths although the rotala butterfly website Zeus mentions gave me a answer it's very good just need some scales. Even though my pH with co2 goes below 7.5 I'd rather use eddha to get use of the maximum Fe content possible in solution,also it's best to fertilise before lights on which is before the co2 pH drop so the plants eat before their hard day's work under the light plus it also gives you flexibility of dosing times as work/life applies. I'll report back after time for results. Thanks to everyone who is participating.
 

FishWorks

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But your surgestion to allow for the the dissociation constant changing with the different pHs so if it's only 50% dissolved dosing double the dose will make the initial dose closer to the target
I just gave it some thought today. Since I estimate I have 90% FE-DTPA at 7.1 PH, I could give it an extra half dose. My original target was 1ppm FE per week, new target would be 1.5 ppm.

I found a link from 6 years ago with Tom saying to increase dosing DTPA 2-3x per week to reach target levels.
However, I don't know the original assumed dosing concentration and frequency in the link, he just says compensate by dosing daily, or 3x per week with DTPA.
link below (scroll all the way down):
https://www.plantedtank.net/forums/11-fertilizers-water-parameters/217705-dtpa-edta.html

Perhaps it would be better to dose .25 ppm twice per day, 3 times a week for an approximate total of 1.5 ppm per week.
 

Zeus.

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@Zeus.'s is the really important point, it doesn't seem very scientific but it works, just watch the plants. Scientists do this, they just call it a "bioassay".
Think Darrel nails with the ''bioassay'' IMO, what is actually happening on the actual [Fe] isnt important and can be difficult to actually confirm what is happening, but if the plants are better for it and no livestock suffer then its a winner. After all thats EI dosing - dose in excess at safe levels and if the plants are doing well you can try cutting back if you wish and find out how much is actually needed but that takes a lot of time and effort and our tanks requirements are changing all the time as well. Its all right looking at dissociation constants with different pHs but these are done in close to distilled water I would of thought, I would bet with the minimum of other ions present and are tanks are far from that esp if you have hard water which if your using FeDTPA or FeEDDHA you will have so its a case of suck it and see as far as I'm concerned, well thats the way I understand it is,unless someone has some great paper that confirms what is actually going on.
 
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So I've been dosing Fe eddha for a few weeks now adding tip of a teaspoon as per recomended on this thread and gaining the slight pink tinge, after a week it looked liked my plants perked up abit more vibrant and my Xmas moss started showing alot more growing tips and java fern has sprouted loads of new shoots so all cushty. Prior to buying and installing puriden filter media I done some reading on ukaps and its been stated a few times purigen removes bio waste and not non bio waste to clarify the water, I've had it in a week the water is alot clearer but.... I no longer get the pink tinge from eddha and the purigen media is looking pinkish so I can only assume that the purigen is removing the eddha? Anyone have any experience using purigen and its effects on their fertiliser's?
 

dw1305

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Hi all,
So I've been dosing Fe eddha for a few weeks now adding tip of a teaspoon as per recomended on this thread and gaining the slight pink tinge, after a week it looked liked my plants perked up abit more vibrant and my Xmas moss started showing alot more growing tips and java fern has sprouted loads of new shoots so all cushty.
Good, that sounds promising.
I no longer get the pink tinge from eddha and the purigen media is looking pinkish so I can only assume that the purigen is removing the eddha?
I don't have any experience with Purigen and iron chelates, but the pink colour would indicate that you are right, and the FeEDDHA is being removed by the Purigen.

Seachem are evasive as to the <"exact mode of action of purigen"> but it probably removes <"molecules by size">. Most large molecules would be organic "wastes": proteins, structural carbohydrates, tannic and humic compounds etc.

All the nutrients we add, other than iron chelates, would be as ions. When you add the salt potassium nitrate (KNO3) it become K+ & NO3-. An ion is a single atom (or simple compound) plus (NO3-), or minus (K+), an electron.

This is <"NaEDTA">, but <"FeEDHHA"> would be similar in size.
salt_acid.gif


cheers Darrel
 
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So basically iron chelate are large enough molecules for the purigen to hold on to them where as other nutrients are simple compounds and slip through the media?
 

dw1305

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Hi all,
So basically iron chelate are large enough molecules for the purigen to hold on to them where as other nutrients are simple compounds and slip through the media?
Yes, that looks fairly conclusive from the pink tinge of the Purigen.

cheers Darrel
 

Zeus.

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So if the Purigen is mopping up the FeEDHHA which I think is fairly conclusive from the observations of Craig, I can see no reason why it should mop up the FeEDTA or FeDTPA as well :rolleyes: not good news for Purigen users
 
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