Iron deficiency with EI

[Jose]

Lets see:
Ardjuna. You are saying that you have noticed the same as me but you give a different explanation/s.
We have both noticed this: If we see what looks like a PO4 deficiency we add more PO4 and solve it. We have seen that EI levels arent always enough.
Now where we differ is in our explanation of why.
You say that this is due to precipitation of PO4 or you also suggest that plants can consume more than EI levels. This could be the case but I dont think so. Precipitation doesnt happen to a huge extent normally for PO4 and most of our tanks dont consume more than EI.
My explanation is that by adding more PO4 (even than EI levels) your plants have easier acces to it and thus the deficiency disappears without touching the CO2. This is because deficiencies are due to a relationship Nutrients-CO2. Both of you are seeing the deficiency as a function of only 1 thing (CO2 for Ian and PO4 for Ardjuna). Both of you are right but not totally since I dont think you explain the whole pictur just half of it. You can solve the deficiency by modifying each of the two variables (PO4 and CO2) separately or at the same time. The point is the defficieny is a function of how much PO4 is in the water for the level of CO2 (relationship CO2-PO4). You could see it the other way around as well but its still a relationship.

 

[Jose]

This could be another way to see it:

For Tom Barrs experiments:
CO2->50ppm (not sure but its just to make a point)
2 ppm of PO4 is enough so as not to get deficiencies
X ammount of light


For another tank
CO2->30 ppm (this is what the person thinks maybe in reality its at 20ppm)
Maybe this person needs 5ppm of PO4 so as not to see deficiencies
same X ammount of light

Im not talking in any case about nutrient uptake here. Just water nutrient levels and plants responses.

Can Ceg take a second to make me stop toying with this idea?

 

[Paulo Soares]

Because EI can no longer be considered non-limiting under every condition

you also suggest that plants can consume more than EI levels

I´m reading all this with very attention and i´m starting to get a bit insurgent.. cause when i started in this hobby i was defending too exaclty what Ardjuna and Tug and others are saying.. (more or less).
From the beggining, I never really accept the "marvelous Ei fairy tail" that everybody was claiming about. I was always reticent, and have some difficult to accept Ei theorys as so simple it was presented.

After a couple of years reading and reading lot´s and amounts of information, and disturbing so many people gathering opinions, (some of you also) i finnaly acepted the fact of Ei be what was being told..
And now ... really.. after reading all this i don´t know what to think. I guess i´ve had enough of this Ei controversial stuff. I only find funny the gentleman in the root of Ei never came to public clarify once and for all this doubts of milions. Cause talking to the guy in his B. Report is not an easy task..
But he is aware of the controversial.

So.. never mind this is me pouring..
I´m going to focus in my tank´s observation and self understanding as i always did since i remember being in this hobby.

A big hug

 

[tug]

I have noticed lately that some of my plants turn white like stayrogen repens and monte carlo. I am double dosing macros and micros. Is there a chance that Iron can become low even with EI?

There are several situations that can cause a plant to grow white/yellow leaves. Iron deficiency, carbon deficiency, nitrogen and even Calcium deficiency. I have also heard that overdosing excel can cause a bleached effect on some plants, stem plants mostly. Without asking Jaap a few questions, I fail to understand how we can help answer the OP.

If Jaap would tell us if he doses liquid carbon or not, this might be the problem - not CO2 or EI.

If you did not read this post concerning EI, then you really should. EI is less likely limiting, not non-limiting.
http://www.barrreport.com/forum/barr-report/estimative-index/5053-confusion-about-ei-and-other-myths
CO2 will always be limited when plants are grown in tanks of water containing fish.
The relationship between PO4 and CO2 while important to understand, fails to answer the question of the OP.

 

[Jose]

I´m reading all this with very attention and i´m starting to get a bit insurgent.. cause when i started in this hobby i was defending too exaclty what Ardjuna and Tug and others are saying.. (more or less).
From the beggining, I never really accept the "marvelous Ei fairy tail" that everybody was claiming about. I was always reticent, and have some difficult to accept Ei theorys as so simple it was presented.
After a couple of years reading and reading lot´s and amounts of information, and disturboing so many people gathering opinnions, (some of you also) i finnaly acepted the fact of Ei be what was being told..
And now ... really.. after reading all this i don´t know what to think. I guess i´ve had enough of this Ei controversial stuff. I only find funny the gentleman in the root of Ei never came to public clarify once and for all this doubts of milions. Cause talking to the guy in his B. Report is not an easy task..
But he is aware of the controversial.
So.. never mind this is me pouring..
I´m going to focus in my tank´s observation and self understaning as i always did since i remember being in this hobby.
A big hug

EI does work and is great. But some people want to know more. You shouldnt have doubts about it. Its made many nice high tech tanks. Its designed to apply it with your eyes closed and thats whats great really.

 

[Jose]

The relationship between PO4 and CO2 while important to understand, fails to answer the question of the OP.

No it doesnt. It could actually be a defficiency (CO2 or whatever nutrient). We dont know. Although I agree thats its gone out of track.

 

[ian_m]

When I use water sample from my tank, and the color doesn't change, then I know there's no PO4

This could be you problem. Hobby PO4 test kits are heavily influenced by other chemicals (both natural and EI) in your tank water, which is why lab grade kits must be used (as per Tom Barr) if you want to get any meaningful reading of actual PO4 in your tank. I think hobby PO4 tests tend to grossly under read in presence of other ions (NO3 tests over read I think) present in tank water, so much so hobby grade test kits will often read zero regardless of actual PO4 levels.

 

[ian_m]

You are dosing Mg ? I have seen numerous cases, with "whiting" & "yellowing" plants, where people have invented their own version of dosing with no MgSO4, as they have incorrectly assumed there water supply was supplying Mg. Just added powered MgSO4 sent the plants back to green in a couple of days.

 

[tug]

Hobby PO4 test kits are heavily influenced by the hobbits through misuse, IMHO. I do not think ardjuna is one of those hobbyists.
Plants having a Mg deficiency would have dark veins with lighter leaf tissue but it's worth asking - a picture would be helpful too.

 

[Jose]

This could be you problem. Hobby PO4 test kits are heavily influenced by other chemicals (both natural and EI) in your tank water, which is why lab grade kits must be used (as per Tom Barr) if you want to get any meaningful reading of actual PO4 in your tank.

As Ardjuna has said they are no good if you need to know absolute values with low error. But they can be useful to measure a quantitative change in concentration. Say if your water has gone from 5ppm PO4 to 1ppm Im sure youll notice it with many test kits.

 

[dw1305]

Hi all,

Do I need laboratory grade test kit to find out whether I have zero PO4 in my water? When I use some ordinary PO4 test kit, and add a little KH2PO4 in the water sample, and the color turn purple, then I know it works. When I use water sample from my tank, and the color doesn't change, then I know there's no PO4. That's all I need to know. No need to use lab grade tests for this simple test as I don't need to know the exact PO4 concentration

You've got to be a little bit careful. Nearly all test kits will work with the added ions from the dissolution of added salts, but like "ian_m" says, the problem comes when you have a solution (tank water) with a range of anions present.

Hobby PO4 test kits are heavily influenced by other chemicals (both natural and EI) in your tank water, which is why lab grade kits must be used (as per Tom Barr) if you want to get any meaningful reading of actual PO4 in your tank. I think hobby PO4 tests tend to grossly under read in presence of other ions (NO3 tests over read I think) present in tank water, so much so hobby grade test kits will often read zero regardless of actual PO4 levels

Tests are better for multivalent ions like PO4--- than they are for monovalent ones, like NO3-, but there are still problems.

You can also get deficiency problems due to the ratio between ions, where you may have non-limiting values of an element, but its uptake is blocked by high levels of another element. This is what you get when you have a large excess of calcium (Ca) ions, blocking the uptake of magnesium (Mg) and iron (Fe), .

Both phosphorus (P) and iron (Fe) deficiencies can occur in solution, mainly because the majority of compounds they form are insoluble.

This is a particular problem in hard water, where you get iron hydroxide, iron phosphate and insoluble calcium phosphate complexes formed. This was the original reason for the development of chelators like FeEDTA for hydroponics, these "trickle" iron ions out over time as the FeEDTA is photo-degraded.

cheers Darrel

 

[Jose]

Hi all,
ardjuna said: ↑
Do I need laboratory grade test kit to find out whether I have zero PO4 in my water? When I use some ordinary PO4 test kit, and add a little KH2PO4 in the water sample, and the color turn purple, then I know it works. When I use water sample from my tank, and the color doesn't change, then I know there's no PO4. That's all I need to know. No need to use lab grade tests for this simple test as I don't need to know the exact PO4 concentration
You've got to be a little bit careful. Nearly all test kits will work with the added ions from the dissolution of added salts, but like "ian_m" says, the problem comes when you have a solution (tank water) with a range of anions present.
ian_m said: ↑
Hobby PO4 test kits are heavily influenced by other chemicals (both natural and EI) in your tank water, which is why lab grade kits must be used (as per Tom Barr) if you want to get any meaningful reading of actual PO4 in your tank. I think hobby PO4 tests tend to grossly under read in presence of other ions (NO3 tests over read I think) present in tank water, so much so hobby grade test kits will often read zero regardless of actual PO4 levels
Tests are better for multivalent ions like PO4--- than they are for monovalent ones, like NO3-, but there are still problems.
You can also get deficiency problems due to the ratio between ions, where you may have non-limiting values of an element, but its uptake is blocked by high levels of another element. This is what you get when you have a large excess of calcium (Ca) ions, blocking the uptake of magnesium (Mg) and iron (Fe), .
Both phosphorus (P) and iron (Fe) deficiencies can occur in solution, mainly because the majority of compounds they form are insoluble.
This is a particular problem in hard water, where you get iron hydroxide, iron phosphate and insoluble calcium phosphate complexes formed. This was the original reason for the development of chelators like FeEDTA, these "trickle" iron ions out over time as the FeEDTA is photo-degraded.
cheers Darrel

Hi Darrel. This is the problem that Tom Barr says hes never encountered any of this problems even in hard water and he says its always due to CO2. Although he sometimes admits that very few people might have this as a minor problem.

 

[ian_m]

Say if your water has gone from 5ppm PO4 to 1ppm Im sure youll notice it with many test kits

No you wont, as pointed out there are other ions in solution other than PO4 that could change as well and affect the result.

 

[Jose]

No you wont, as pointed out there are other ions in solution other than PO4 that could change as well and affect the result.

You are measuring a change. The rest of ions were there when you did test 1 and are still there when you do test 2. You have more or less the same ammount of "noise" in both experiments.

 

[tug]

Sorry, I posted the wrong link.

I could say that EI is (much) LESS limiting than most other methods.
That would be a much more accurate statement.

http://www.barrreport.com/forum/bar...growth-optimal-test-from-paul-krombholz/page2

 

[ian_m]

The rest of ions were there when you did test 1 and are still there when you do test 2

How do you know, the other ions will have changed as well, giving a false result. You are trying to get one result, the PO4 level, from two unknowns, PO4 and other ions, not possible to get a single reading.

 

[Jose]

How do you know, the other ions will have changed as well, giving a false result.

Wed have to know what ions interfere with PO4. but chances are their conc doesnt change alot. Unless its NO3 or K

You are trying to get one result, the PO4 level, from two unknowns, PO4 and other ions, not possible to get a single reading.

You dont need an absolute number. You will see the difference (plant uptake).

 

[ian_m]

Wed have to know what ions interfere with PO4. but chances are their conc doesnt change alot. Unless its NO3 or K

Loads of false assumptions here.
1. We don't know what ions in the tank interfere with the PO4 test, but we know they do.
2. How do you know the other ion concentration doesn't change ? The pH of your tank may vary hourly with say CO2 and light, this will certainly change ion concentrations which will affect test results.
3. NO3 & K may or may not change and may or may not affect the PO4 reading.

 

[Jose]

Anyway this is far from the point of the tread. Im not going to keep defending test kits since I myself dont use them.

 

[Jaap]

A bit more info about my 40 litre tank...

1. A TMC GroBeam 1500 Ultima tile, 40cm from substrate and at 60% intensity
2. Substrate is JBL manado
3. My kH is around 9
4. I am pumping CO2 at such a high rate which is not measurable by bubbles per second. It is connected onto an inline diffuser which is connected on the inlet of the filter. Because the CO2 pumped inside the filter is not dissolved completely, CO2 bubbles are blown out of the filter every 5 minutes or so. CO2 system has no leaks, triple checked it. It is impossible to pump more CO2 into this tank. Drop checker is yellow and pH drops by 1.2 units in an hour!
5.The filter is 1000 L per hour and has only sponges and ceramic media
6. Filter is connected to a spray bar along the length of the back of the tank. Spraybar points directly straight towards the front glass and it is situated 1-2 cm below water level
7. In my macro solution I have KNO3, KH2PO4 and Epsom Salts so yes I also dose Mg
8. I do not dose Excel

Could Hydrogen Peroxide cause this whitening? I added 4ml with a syringe on a few plants including the stayrogyne repens and montecarlo.

Thanks