How to dose PMDD

[heavenhell]

Hi, i just started reading abt PMDD but got confused in how to dose. Lets say that my tank is 100L, so to acheive 0.1ppm of Fe, i need to dose 10mg of Fe is it?

Dr Mallick LushGrow-Micros comes in a 120ml bottle, it state 21,253mg/L of Fe. So 1ml of tis solution would give mi 21.253mg of Fe?

so to achieve 0.1ppm Fe in 100L tanks, i need around 1/2ml of solution?
Please correct mi on any mistakes. Thanks a lot.[:]

[bttay]

----------------
On 8/9/2003 8:20:12 PM

Hi, i just started reading abt PMDD but got confused in how to dose. Lets say that my tank is 100L, so to acheive 0.1ppm of Fe, i need to dose 10mg of Fe is it?

Dr Mallick LushGrow-Micros comes in a 120ml bottle, it state 21,253mg/L of Fe. So 1ml of tis solution would give mi 21.253mg of Fe?

so to achieve 0.1ppm Fe in 100L tanks, i need around 1/2ml of solution?
Please correct mi on any mistakes. Thanks a lot.[:]
----------------

1ml contains 21.253mg of Fe. If you pour 1ml of the solution into your 100L tank, the concentration would be 21.253/100 = 0.21253mg/L (ppm). So if you want to achieve 0.1ppm you should pour only half ml of the solution. Yes. I think you are right!

For precise measurement in ml, you may use a medicine dropper available at Apex or Guardian. Accuracy up to 0.01ml. Only cost you $2 plus.

[heavenhell]

I also asked this question at other forums and someone gave mi tis ans
Quote:

From the specs, they are using Fe-EDTA, which contains 13% chelated iron.

1. You need to convert mg/L to g/L, and that gives you 21.253 g/L.
2. Multiply the above value by 13%, which gives you 2.76289 g/L of Fe.
3. Therefore, 1ml of this solution in a 100 litre tank will gives you [(2.76289g/L)*(1000mg/g)]*[(1ml)*(l/1000ml)]/(100l) = 0.02763 ppm



so which is correct?

[geoffrey]

0.02763 is correct.

[heavenhell]

Thanks . Another question, are other elements like Mn in EDTA form too? Do i use the same method to calculate?

[PeterGwee]

You don't need to be anal with Fe/traces.....as long as the other stuff like light, CO2, N, P and K are in good range especially N and CO2, you can dose more traces to find the limit in which there would be no improvement to plant growth if more is added.

[eric_kclee]

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On 8/14/2003 9:19:22 PM

I also asked this question at other forums and someone gave mi tis ans
Quote:

From the specs, they are using Fe-EDTA, which contains 13% chelated iron.

1. You need to convert mg/L to g/L, and that gives you 21.253 g/L.
2. Multiply the above value by 13%, which gives you 2.76289 g/L of Fe.
3. Therefore, 1ml of this solution in a 100 litre tank will gives you [(2.76289g/L)*(1000mg/g)]*[(1ml)*(l/1000ml)]/(100l) = 0.02763 ppm

so which is correct?
----------------

I need to seek opinion from all.
I too have the above question, and I email Dr Mallick to ask about the Fe content on both Lushgro AQUA and Micros, is it 1.683g/l (21.253g/l for Micro) effective Fe or 0.13x1.683g/l?

And this is what he answer
Quote:
--------------------------
Dear Eric

Thanks for your mail dt 8 Sep 2003 19:50:51 -0700 (PDT)
reg LUSHGro AQUA and MICROS

Thanks for patronizing our products.

The 'other minerals' with 'traces quantity' refers to some
imprities that come with the processed minerals. They are
mostly elements like Cobalt, etc... and their contents are
almost negligible.

Both LUSHGro AQUA contains 1.683g/litre of elemental Fe
derived from Fe-EDTA which contains 13% Fe.

Warmest regards

Dr. Mallick
-------------------------

It sounds like the 1.683g/l is the effective Fe amount (read '1.683g/l of ELEMENTAL Fe') and we don't have to multiply it with 13% for PPM calculation.

Can everyone agree to that or can you help to apprehen this email (I may understand it wrongly)?

Thanks

[eric_kclee]

I have asked Dr Mallick for further clarification. This is what he wrote.... (conclusion: no need to multiply 0.13)

------------------------------------------
Dear Eric

Kindly refer to your e-mail dt Wed, 10 Sep 2003
Subject: Re: About LUSHGro AQUA and MICROS
-----------------------
Could you please elaborate the following point?
'LUSHGro AQUA contains 1.683g/litre of elemental Fe
derived from Fe-EDTA which contains 13% Fe. '

Does it mean I use 1.683g/l as full effective amount
of Fe? and use 1.683 straight for ppm calculation?

That means I don't have to use 0.13x1.683=0.219g/litre
as the effective Fe?

Some people read it as 1.683 of Fe-EDTA, to get the
exact Fe, then become 0.13x1.683=0.219g/litre. Is this
correct?
-----------------------------------
Thanks for contacting us to clarify your doubts.

No need to multiply. The amount stated is the ACTUAL Fe
content in the packed solution in the bottle.

Fe-EDTA is only the source of Fe.

LushGro-Aqua solution in the bottle contains 1.683 GRAMS /
litre or 1683 MILLIGRAMS / litre or 1683 ppm of Fe.
......
-----------------------------------------------------

[Plantbrain]

PMDD:
Using a trace measurement and iron as proxy with a test kit is simply plain wrong.

PMDD has macro nutrients in it. These are far more critical to plant growth and much less problematic to test for(PO4, NO3 etc) than a funny trace metal which eludes any test kit.

I don;t have an all in one mix. I add the macros dry and the traces I mix 500mls of H2O with 2 tablespoons of the dry CMS trace mix for a trace mix.

The issue at hand here is what is enough bio available iron? Not much. But the issue also has another problem, iron complexes with about 20 other ions in solution. This is not including organic compounds. Hoe much is enough then? Test are influenced by these complexes.

Testing for iron after 12 hrs often yields no iron. Maintaining any sort of residual is a lesson in futility.

Main thing is to dose traces after everything else is in a good range, therefore dosing macro nuteient separately is wise choice and presents less math problems and chemistry errors which folks are prone to.

Add 5mls of traces to every 80 liters of tank 2-3x a week depending on plant load, light.
If you have low light, less than 2w/gal, try once a week.

Add the other nutrients, like KNO3, K2SO4 etc dry.

Regards,
Tom Barr