Adding Additional Iron - Advice Please.

[Quetzalcoatl]

Hi there.

I am interested to see the effects of dosing additional Fe. I have decided to experiment and to see for myself if there is any real improvement in plant health/colouration.

I have acquired Chelated Iron 13.2% and am eager to start dosing. Trouble is I don`t know how much to add, and when? Is it best to add the Fe to my current Trace solution and add accordingly? Or should I be making up a separate solution and dosing independently of addition traces?

My tank is 180ltr and is moderately planted. I`m dosing full Ei and inject Co2.

Any help on this matter would be most appreciated.

 

[dw1305]

Hi all,
You just need the workings from the other "Chelated Iron" post: <http://www.ukaps.org/forum/viewtopic.php?f=11&t=19201>

Because it is 13.3% Fe you have EDTA-FeNa.3H2O. .........So 37.7g of FeNa-EDTA made up to 1000cm3 in water stock solution, and that stock solution used at 10cm3 in 100 litres supplies 0.5ppm Fe3+.

Using the 37.7g in 1000 cm3 stock sol. of FeEDTA, to get 0.5ppm Fe you need to use 1cm3 per 10 litres of tank.

Is it best to add the Fe to my current Trace solution and add accordingly? Or should I be making up a separate solution and dosing independently of addition traces?

You also need to bear this in mind (via the wonderful "James' Planted Tank" <http://www.theplantedtank.co.uk/traces.htm>)

Also of interest is what chelators have been used in the trace mixes. This can be important depending on the hardness of your water. DTPA and HEEDTA chelators last longer in hard water compared to the common EDTA ones. This is mainly important for the iron because whilst it is still chelated it is available to the plants, but once 'free' it readily reacts with several compounds (mainly phosphate) creating an insoluble precipitate of iron(III) that is either filtered out by the filter or drops into the substrate. This has the effect of removing iron from the plant's reach. Eventually the iron(III) compounds in the substrate are reduced to iron(II) becoming available to the plant's roots. This insoluble precipitate looks like white hazy water and can happen sometimes soon after dosing a trace solution that contains iron EDTA.

cheers Darrel

 

[Quetzalcoatl]

Cheers Darrel.

I`ve read the other post previously, and had actually posted there a few days back but got no response. I figure with it being old it had been forgotton.

Without sounding like a complete fool I was struggling with the mathematics! 😳 It never was a strong point of mine. I will have to study it in some detail and see if I can make sense of it. I`m sure it will become apparent. Eventually?

I was also interested to know when, and how to go about adding the additional Fe. Is it ok to add to the trace mix when making a fresh solution, or is it best dosed separately?

 

[ceg4048]

If you struggle with the math then you need to make it easier for yourself and avoid complications. Fe is a micronutrient and therefore it does not really have too much impact compared to a macronutrient like Nitrogen which is about 50X more important. So you will see a much greater difference in plant coloration and growth rates dosing more N than you will see dosing more Fe.

It doesn't really matter if you are as precise as Darrel's calculations permit. If you want to see the effects of more Fe then just add any arbitrary amount consistently and observe the effects. In fact the difficulty in doing this has nothing to do with calculations or even in deciding how much to add. The real trick is control. We do not have full control of our tanks and therefore we struggle to make heads or tails out of what we observe happening in the tank. So the real difficulty is in determining whether or not the improvements or decline in plant health was due to adding X amount of ABC or whether the observed effects was due to an unintentional variation in CO2, or in flow/distribution or a thousand other things which have a bigger impact than product ABC. Without control, our conclusions are almost always speculation. In order to filter out these effect, or to average them out, so to speak, the thing to do is to repeat the test several times and compare results over time so that in a way, statistically, things will even out.

In any case, just add an extra few grams of your iron powder, observe the tank for a few weeks and as long as you record or remember how much extra you added, then we can always figure out the numbers later. I don't see why this has to be complicated at all. It is science, but it doesn't have to be rocket science. 😉

Cheers,