Plant deficiencies and the Fe Experiment

[keef321]

@Aquarium Gardens is proof you can have fantastic success with very high KH water (dKH 13+). It's definitely high tech... not sure what they do for iron.

Totally agree they are accomplished aquascapers and I am always impressed when I visit. They inform me that they do not add any extra iron, and simply dose APT complete as per the instructions. I have tried that in my water and it was not a pretty result 😛

Perhaphs they keep replacing bits of the substrate and adding tabs? Again, I found my substrate appears to lose its ability to supply iron pretty quick.

 

[jellybean]

In my shrimp tank I keep dGH around 4.5 (it may be a lot closer to 4 due to uptake, but I target my WC water 4.5), pH 6.2 and fair amount of Calcium in the food sources - both snails and my diverse shrimps are thriving.

@MichaelJ What do you feed them?

 

[_Maq_]

@Aquarium Gardens is proof you can have fantastic success with very high KH water (dKH 13+). It's definitely high tech... not sure what they do for iron.

A well-looking tank is not the full answer. When you look at it, you appreciate good health of the plants which are present. What you don't see are the species which failed to survive there.

 

[MichaelJ]

@Aquarium Gardens is proof you can have fantastic success with very high KH water (dKH 13+). It's definitely high tech... not sure what they do for iron.

A well-looking tank is not the full answer. When you look at it, you appreciate good health of the plants which are present. What you don't see are the species which failed to survive there.

Right. Well, I think when you add CO2 you can pretty much get away with anything in terms of water parameters... we've had members with great looking high-tech tanks running them on liquid rock tap-water in the 18 dKH/dGH range.... as proof, and we've had a lot of "friendly" scoffing in the past at members (including myself) for being overly focused on water parameters - mostly - if not exclusively by -other CO2 users 🙂

Yes, you can certainly keep a decent selection of easy plants at high dKH in a low-tech tanks, its just not nearly as rewarding as when you provide the plants more natural water parameters.

Cheers,
Michael

 

[MichaelJ]

@MichaelJ What do you feed them?

A couple of times a week Aquatic Arts Algae wafers, Dennerle Protein sticks (shrimps need protein and while it sounds morbid, it keeps the large shrimps from preying on shrimplets), Dennerle Mineral sticks, blanched kale and zucchini slices, plenty of Botanicals (dried almond leaves) are always available and decomposing at various stages in the tank. Shrimps pretty much eat all the time 🙂

Cheers,
Michael

 

[MiZubov]

2) I keep phosphates low (0.1 mg/L or so) and take care not to dose phosphate simultaneously with iron (and other transition metals). Also, I do not use filters.

Why is there no iron binding at a phosphate concentration of 0.1, but it occurs at higher concentrations? Why does the concentration matter?
Thanks a lot.

 

[Zeus.]

Why is there no iron binding at a phosphate concentration of 0.1, but it occurs at higher concentrations? Why does the concentration matter?
Thanks a lot.

Studies on diffusion have shown that the activation energy and pre-exponential factor in the Arrhenius equation can systematically vary with concentration as the interdiffusion coefficient changes with concentration.

So in lay terms it's more likely to interact at higher concentrations and at low concentrations it is less likely to occur, I would assume below a certain concentration no interaction occurs

 

[dw1305]

Hi all,

So in lay terms it's more likely to interact at higher concentrations and at low concentrations it is less likely to occur,

That is it, it is just a <"numbers game">.

cheers Darrel

 

[MiZubov]

Studies on diffusion have shown that the activation energy and pre-exponential factor in the Arrhenius equation can systematically vary with concentration as the interdiffusion coefficient changes with concentration.

So in lay terms it's more likely to interact at higher concentrations and at low concentrations it is less likely to occur, I would assume below a certain concentration no interaction occurs

Could you give an example of the actual operation of this equation in our wonderful hobby? For example, with the same phosphates and iron themselves..

 

[Zeus.]

Could you give an example of the actual operation of this equation in our wonderful hobby? For example, with the same phosphates and iron themselves..

Well my guess would be at higher concentrations the cations have be moving at higher velocities and may have more kinetic energy and this may provide enough energy to displace the DTPA/EDTA from the Fe and a Fe phosphate compound forms. This compound may have a higher bond strength which plants are unable to break so render the Fe unavailable.

N.B, the above is just my theory of top of my head 😉

 

[Andy Pierce]

Studies on diffusion have shown that the activation energy and pre-exponential factor in the Arrhenius equation can systematically vary with concentration as the interdiffusion coefficient changes with concentration.

Just sayin' but I have no idea what any of that means. 😜

 

[John q]

Could you give an example of the actual operation of this equation in our wonderful hobby? For example, with the same phosphates and iron themselves..

I can't. I'll admit it 😌

But.. John's law states that if you are trying to balance a Po4/Fe reaction in an aquarium there's more chance one will be burnt at the stake.
Dose more, not less might be the Answer.

Sadly there are very few scientific studies that supports a perfect p/fe ratio in aquatic plants.

 

[MiZubov]

MnO2 may get reduced in the sediment just like Fe(OH)3 and other iron compounds, and this is the way plants obtain most of both metals in natural conditions.

Hello, I did not really catch the idea of why manganese is washed out of the sediment and why this contributes to the production of these metals by plants. Can you explain this point? Thank you.

 

[dw1305]

Hi all,

Hello, I did not really catch the idea of why manganese is washed out of the sediment and why this contributes to the production of these metals by plants

It isn't washed out of the sediment, it just becomes plant available. It is only Mn++ ions that plants can utilise. Under aerobic, alkaline ("oxidising") conditions the manganese will remain as the oxide (MnO2) and unavailable to plants.

The manganese dioxide (MnO2) is reduced (under acidic, anaerobic conditions) with the oxygen being used a an electron donor and manganese ions being liberated <"Manganese in Plants: From Acquisition to Subcellular Allocation">.

Plants produce zones of <"fluctuating REDOX value"> around their roots that can both help with uptake of nutrients and <"protect against toxicity">.

cheers Darrel

 

[MiZubov]

That is not to say that we want the share of organic matter in the substrate higher than units of per cent.

But aquariums with soil contain a lot of organic matter and there is nothing wrong with that. Or..?

 

[MiZubov]

All that I know, is locally to me if you are low tech, those that have success are mainly dosing iron (sometimes without even knowing it), and if co2 injected it needs to be chelated.

Why does the presence of CO2 determine the need for iron chelation? Shouldn't it be the other way around? The higher the pH, the greater the need for chelation?

 

[keef321]

Why does the presence of CO2 determine the need for iron chelation? Shouldn't it be the other way around? The higher the pH, the greater the need for chelation?

Sorry, I might have mis-wrote that section…my English writing skills are not always the best 😂 What I perhaps was intending to say is that with both a high PH & co2 the need for a chelated iron is even more important, as co2 injection normally equates to higher levels of light, which drives growth faster…..hence you will see iron deficiency quicker.

 

[Zeus.]

Sorry, I might have mis-wrote that section…my English writing skills are not always the best 😂 What I perhaps was intending to say is that with both a high PH & co2 the need for a chelated iron is even more important, as co2 injection normally equates to higher levels of light, which drives growth faster…..hence you will see iron deficiency quicker.

👍
As many a low tech tank users find there is only the need for the standard Fe chelate, as they dont have Fe related issues/problems

 

[MiZubov]

It isn't washed out of the sediment, it just becomes plant available. It is only Mn++ ions that plants can utilise. Under aerobic, alkaline ("oxidising") conditions the manganese will remain as the oxide (MnO2) and unavailable to plants.

It turns out that in a planted aquarium, is it necessary to have an anaerobic zone in the ground?

 

[MiZubov]

👍
As many a low tech tank users find there is only the need for the standard Fe chelate, as they dont have Fe related issues/problems

What is standart chelate for Fe? DTPA?