# How much iron Fe is enough



## Edward (May 25, 2004)

original thread



> As I see it "direct sunlight causes algae"? No. The sunlight CAN be the trigger, but not directly responsible. The question is set an ambient stable along the time, because I think is fundamental daily fertilizing.


Hi Trebol-a
I too believe strongly in daily dosing routine where plants can utilize the fresh nutrients.



Trebol-a said:


> Fertilizer: well, just i have trying at low levels of No3. But in "standart" situations add everyday: N 2 ppm - P 0,03 ppm - K 3 ppm
> Fe: 2-3 doses per week, but low levels.... about 0,03 ppm every doses.
> Trace: very irregular, every 20-30 days add 1 ml Flourish.


You have done one of the most important experiments in aquatic history. 
The common trend of dosing Fe under much lower light then your Sun is 0.1 - 1 ppm and some suggest even more, up to 2 ppm of Fe.
Personally (PPS), I dose 0.01 ppm of Fe daily under high light and 0.006 ppm under low light. Most people argue that such low Fe causes deficiencies. Thanks to your experiment, my system of low dosage proves to be correct and is consistent with your observation.

0.03 ppm Fe - Direct Sun
0.01 ppm Fe - 3 to 6 Wpg
0.006 ppm Fe - 1 Wpg

Thank you
Edward


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## Trebol-a (Dec 6, 2004)

Hi Edward, perdon me the delay but I need took a week off 

I´m not a any expert, but i like make a lot of experiments!  I agree.At previous experience always got algae with high levels of iron. at least in my situation the standart recomendation of 0,1 mg/liter or more :-s never work. (really, Are iron test necessary?) This always caused brush algae.
Yes, the iron and the light are directly connected but the all this depend of N levels, if you set low your N you dont need much iron. Personally, when i turn down 0,03 ppm AND N at 2-3 ppm EVERYTIME appear deficiencies then, why more?
High light cause the consume nitrogen and later the need of iron. All this, of course, depend of amount/type of light, plants, water, etc... The true is what the deficit of iron is very easy repair, but the excess not. i think .....


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## plantbrain (Jan 23, 2004)

Trebol-a said:


> Hi Edward, perdon me the delay but I need took a week off
> 
> I´m not a any expert, but i like make a lot of experiments!  I agree.At previous experience always got algae with high levels of iron. at least in my situation the standart recomendation of 0,1 mg/liter or more :-s never work.


If high Fe causes algae, where is my algae?
Claus from Tropica mentioned that every tank he saw in SF was lacking traces, they typically dosed very low PMDD range Fe, I dosed much high levels. Some folks like the colors with less, I like the richer traces.



> (really, Are iron test necessary?) This always caused brush algae.
> Yes, the iron and the light are directly connected but the all this depend of N levels, if you set low your N you dont need much iron.


Why is that? Because you are N limited. Excess Fe makes little difference or PO4 etc.



> Personally, when i turn down 0,03 ppm AND N at 2-3 ppm EVERYTIME appear deficiencies then, why more?
> High light cause the consume nitrogen and later the need of iron. All this, of course, depend of amount/type of light, plants, water, etc... The true is what the deficit of iron is very easy repair, but the excess not. i think .....


What test kit is accurate with Fe to 3ppb?
Try trace dosing without the Fe, then Fe alone.
Also consider the plant, rooted vs non rooted Fe sources.

Regards, 
Tom Barr


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## shalu (Oct 1, 2004)

plantbrain said:


> What test kit is accurate with Fe to 3ppb?


0.03ppm is 30ppb, but that does not matter.

I am not sure how Edward drew the conclusion either. If we use algae growth as a criterion like Trebol-a did, then many of us high Fe dosers aren't overdosing by that standard, because we don't see much algae with very high Fe.

I use plant color as my guide, if more Fe improves color, then I dose more. I like r. macrandra to be deep blood red, not pink, I did not need low NO3 to get that color.


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## Trebol-a (Dec 6, 2004)

plantbrain said:


> What test kit is accurate with Fe to 3ppb?


 Hi Tom, of course, I don´t use test. I dose the 1/3 recomended for *Flourish Iron* from set up the tank at 0,1 ppm / 3 = 0,03 ppm ... approx 



plantbrain said:


> Excess Fe makes little difference or PO4 etc.


 Sorry, i don´t understand this.


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## plantbrain (Jan 23, 2004)

shalu said:


> 0.03ppm is 30ppb, but that does not matter.
> 
> I am not sure how Edward drew the conclusion either. If we use algae growth as a criterion like Trebol-a did, then many of us high Fe dosers aren't overdosing by that standard, because we don't see much algae with very high Fe.
> 
> I use plant color as my guide, if more Fe improves color, then I dose more. I like r. macrandra to be deep blood red, not pink, I did not need low NO3 to get that color.


Opps, I saw the 0.006ppm and thought 3ppb instead of the 30ppb. So 6ppb....

I've always held that the other parameters should be kept within a range and then you manipulate the variable of interest to acheive the desired look or find the point where adding more does not produce a positive effect any longer. That's basic stuff. I did this years ago with test kits, namely a battery of Lamotte's and Hach's. So did others. We found the failings of many test kits, Fe was the worst. It does not tell you what you need to know.

Hence the notion of getting the other nutrients in good shape and giving no less than 3 weeks to determine the dosing of trace mix's effect and impact.

There are ways around testing, but I did the testing first for a long time. When we hit a road block, we adjusted the method tom account for the goal we were after. You can do this same method for any of the nutrients.

Reduction of NO3 and keeping it low and stable is possible. Less light, non CO2, more fish load, regular feeding and testing or the use of indicator plants like M umbrosum are useful and provides more wiggle room. You can easily add some K2SO4 in place of KNO3, you can reduce the ratio of KNO3 from 100% to 50/50, or 25/75 etc..... but my Rotala, ES and other reddish plants are also quite happy and red with higher nutrient levels.

T-

As far as excess Fe/PO4, this makes little(any?) difference in terms of algae or poor plant health. I'd even suggest it makles the tank better and the algae less prevalent, green spot particularly.

When discussing Fe........folks need to consider the chelator at play here.
ETDA, DTPH, gluconates etc, all have different properties and availabilities to plants, most of the Fe is not getting to the plants in many cases. A great deal precipitates and complexes. While the test kit might pick it up, this does not mean nor imply that it is bioavilable.

The same is true for organic bound N and P vs inorganic(and highly plant available) N and P. DON/DOP vs DIN/DIP.

Most test kits measure total N, P, Fe etc.

Flourish has a weaker chelator than most trace mixes, while this allows the plants to get it easier, it also falls out and becomes oxidized more easily as well.

Still being a trace, not a lot is needed and contributions from sources such as the substrate play a role as well as light intensity etc.

So you begin to need to be very careful in the assumption since traces are much tougher/longer to see plant changes in versus something like NO3 or CO2. Contamination becomes a huge issue at ppb ranges and it does not take much to make large differences when the quanities are so small.

3 weeks in a minmum time frame for fast growing weeds when judging the trace mixes.

Try TMG also as well as other traces with different chelators to get a feel for things if you are interested.

Regards, 
Tom Barr


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## averater (Dec 14, 2004)

how much is a high dose of iron? 0.1ppm? 1.0ppm?


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## plantbrain (Jan 23, 2004)

I'd say 1.0ppm estimation is high vs 0.1ppm estimation which might be considered low by some. 

Plants really don't need much, but we add more and get a positive response from the plants beyond thier needs due to other issues than mere estimations of concentration level and the plant's needs.

This is due to other chemical issues than uptake.
The main issue with any measurement is what is the bioavailable nutrient levels, test kits we use seldom measure these things. In many cases it does not matter, but when you begin to dose smaller quanatities and add smaller amounts it can become a relevant issue.

Also Fe is use as proxy for the other 1/2 dozen traces, these are also needed but are not measured.
Adding excess amounts can address any deficencies. I have added more than 1ppm estimated many times over many years and have never seen any adverse critter/fish effects/impacts.

And regarding plants, I've never seen any negative issues associated with high trace dosings, no algae, no issues and healthy colorful growth, nice sheen. 

Regards, 
Tom Barr


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## Zapins (Jul 28, 2004)

Just out of curiosity, what do you think makes Trebol-a's tank tick, so to speak. It seems that his method of dosing and his tank have been established for a long time, rather then just a few weeks (enough for deficiencies to show up). 

There don’t seem to be any long term problems with his way, what is your take on this?


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