# Iron Dosing



## jameson_uk (16 Feb 2020)

I am just checking I have my calculations right as reading another thread I am now not sure I am adding the right amount of iron....

@Zeus. kindly provided me with some FE EDDHA which the manufacturer said


> To provide 1 ppm of iron you need to dissolve 15 grams of Solufeed Fe 7.0 EDDHA in 1,000 litres of water.


I mixed up ~18.75g of this with 250ml deionised water which works out at 5,000 ppm? (4,000 times more concentrate and 1.25 as much)

My tank is 180l so each ml dosed would be diluted by a factor of 180,000 (I know the actual volume is less).   So at 5,000 ppm going in being diluted by 180,000 I would need 18ml a week to be adding 0.5 ppm???

Is this actually the right amount to get EI levels?   (I have actually been doing about 10ml as tank is lower tech, there is some iron, albeit it might not usable, in the trace mix in my main ferts and presumably a little in the tap too)


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## Zeus. (16 Feb 2020)

jameson_uk said:


> I mixed up ~18.75g of this with 250ml deionised water which works out at 5,000 ppm? (4,000 times more concentrate and 1.25 as much)



So Fe EDDHA 7% - so 18.75 /100 gives mass per percent, Fe is at 7% so 18.75g /100x7 = 1.3125g/Fe. or 1312.5mg/Fe. add to 250ml so 1.3125g/Fe. x1000/250 = 5250mg/L Fe. or 5250ppm Fe.

 Concentrate solution is 5250mg/L Fe. so 1.0 ml = 5250mg/1000ml = 5.25mg Fe. So 6ml = 21x6 = 31.5mg Fe. and 18ml = 21x18= 94.6mg Fe.

Tank is 180l

so 6ml dose of concentrate = 31.5mg/180L = 0.175mg/L Fe. or ppm Fe. three doses per week yeilds 0.175 x 3 = 0.525 mg/L Fe. or ppm Fe.

So I would say your maths is correct 



jameson_uk said:


> Is this actually the right amount to get EI levels?



its in the right order of magnitude for EI - if your water is very pink at end of week reduce Fe. dose and if clear increase dose and watch the plants


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## jameson_uk (19 Feb 2020)

Zeus. said:


> its in the right order of magnitude for EI - if your water is very pink at end of week reduce Fe. dose and if clear increase dose and watch the plants



This is another area being colourblind makes things interesting....  I have been informed that after adding the water is a bit reddy / brown (but more brown) which makes me think I have made it come out of solution straight away.

I have been adding it at the same time as my main ferts after weekly water change.  My main ferts have ascorbic acid which I believe is to reduce the pH and stop the Potassium (?) Making the iron ineffective?

Should I be dosing at a different time or should I have done something to stabilise the iron liquid mix (I did use distilled water rather than tap)


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## Craig Matthews (19 Feb 2020)

The ascorbic acid reduces the pH to protect the ferts from precipitating and going mouldy I think. Po4 and Fe will react with one another regardless that's why we dose them on different days macro then micro, waters pH determines what source of FE you will need and it precipitates if it exceeds its chelate pH range.


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## jameson_uk (19 Feb 2020)

Craig Matthews said:


> The ascorbic acid reduces the pH to protect the ferts from precipitating and going mouldy I think. Po4 and Fe will react with one another regardless that's why we dose them on different days macro then micro, waters pH determines what source of FE you will need and it precipitates if it exceeds its chelate pH range.



I thought the Potassium Sorbate was to stop the mould and the acid helped stopping them react?
This is the roll your own ferts which are similar to Tropicas.   These are mixed macro and micros.  (http://www.theplantedtank.co.uk/allinone.htm)


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## Craig Matthews (19 Feb 2020)

I've honestly never seen that before this is new to me I think you need someone more experienced in chemistry than I. when you dose the aquarium reactions may occur and besides doing all in one like this means more expense buying pottasium sorbate etc.


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## jameson_uk (20 Mar 2020)

Interested in any other thoughts on dosing.

With the all in one solution I am dosing should I avoid adding the iron at the same time?  

When I next mix up a batch would I be able to add the Fe as part of the all in one mix or is this a no no?


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## dw1305 (20 Mar 2020)

Hi all,





jameson_uk said:


> When I next mix up a batch would I be able to add the Fe as part of the all in one mix or is this a no no?


When I used to do more of this sort of thing for work, I used to keep the "macros", "micros" and "iron" as three separate solutions, but I used to make up a big batch of trace element solution and FeEDTA, and they would last be through three or four batches of macros.

An "All in one" should be all right as long as you acidify it and store it in the dark. The most secure way is to use an <"amber glass reagent bottle"> placed in a  cupboard, but you can use any bottle and just wrap it in aluminium foil.

From: <"Photodegradation of FeDTPA in Nutrient Solutions. I. Effects of Irradiance, Wavelength, and Temperature"> 





> It is exposure to light that photodegrades the ligands of the chelator and releases the Fe+++ ions into solution.Irradiation of FeDTPA-containing nutrient solutions by a fluorescent plus incandescent light source resulted in the loss of both Fe-chelate and soluble Fe, the formation of a precipitate that was composed mostly of Fe, and a rise in pH. The rate of Fe-chelate photodegradation in solution increased with irradiance intensity and with solution temperature under irradiation, but irradiance had the greater effect. Fe-chelates absorb in the blue and UV regions of the spectrum. Removal of these wavelengths with a spectral filter eliminated photodegradation.


cheers Darrel


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## Aqua sobriquet (20 Mar 2020)

All a bit too technical for me, how many Holland & Barrett 20mg Gentle Iron tablets do I add a month to a 30L Nano?!


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## Jayefc1 (20 Mar 2020)

jameson_uk said:


> I thought the Potassium Sorbate was to stop the mould and the acid helped stopping them react?
> This is the roll your own ferts which are similar to Tropicas. These are mixed macro and micros.


I make this up in a 500ml mix with no precipitating
At all I add 0.2 grams of Ascorbic Acid and Potassium Sorbate then add 20ml every 3 days to my 140ltr 10ml to the 60ltr and 5 mg to the 35 litre with no issues have a look at my tanks 

https://www.ukaps.org/forum/threads/scape-corner.57131/page-16#post-590547


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