12.5 micromol Fe2 to ppm?

[Gilles]

Hi, i have this iron concentrate, which states: 1000grams in 1000l water gives 12.5 micromol.
So if the molar weight of Fe is 55.847 (periodic table) then how do i know how much ppm it gives?

For instance; if i have 1 gram in 1 liter water; how much ml do i need to raise the ppm of a 'x' liter tank by 'x'?
If you know what i mean...

Thanx for any help
Gilles

 

[Philosophos]

1 micromol = 1/1000000th of a mol.

So then...

= 55.847 * 12.5 / 100000 * 1000 (conversion to mg)
= 6.980875mg/L Fe

 

[Tom Barr]

Something is not right.
1 kilo of Fe dry mix into 1 kilo of water only gives 6.98 mg/L?

Sure it's not 1 gram of dry mix into 1 liter?

Most chelated Fe powders are 7-11%,a few might be up to 22% Fe.
DTPA is typically 10% etc.

So adding 1 gram of dry DTPA Fe in 1 liter of water will add 100 mg/L of Fe since 10% of the mass is Fe.
Note, there's no moles here in the above example, just mass, % and volumes.

Adding 1 ml of this stock solution into 100liter tank will = about 1ppm or 1 mg/L.
With different chelators, this might be 0.5-0.7 up to 2.2 or so.

It might be very diluted with other items to get such low levels, but I'd check the label on the Fe bag again and make sure.
Does not sound rigtht

Regards,
Tom Barr

 

[Gilles]

Hi Tom,
1 kilogram of dry Fe 7% in 1000 liters water, so not 1 kg. Do you know enough then?

So if i read your post correctly, 1 gram in 1 liter and then 1ml of that solution will add 0.7ppm?

And if i add 20 grams to 500 milliliter of water i get a sollution of 28000ppm and 1ml will add 56ppm of Fe2 in a 100l tank?

How i got to this:
Fe concentration: 0,7
Grams: 20
Milliliter: 500
Resulting stock: 28000 (=0.7*20*1000)*(1000/500) = (grams * weight * 1 liter) * (1 liter / size of stocksolution)
One ml adds: 56ppm in a 100 liter tank (=28000/500)

Wow, thats massive... No wonder my water colors red.

 

[Tom Barr]

Sorry, I thought it said 1.000 Liters for some reason. Not many make 1000 liters worth at a time.
My fault there. I think going from mls to liters in the dilution is missing.
28,000mg/l stock solution should be 100 liters x 100mls/1liter.
So it should be a factor of 10,000X less than the stock solution, for each ml added to a 100 liter's worth of aquarium.

28,000/ 1000mls/1 liters*100 liters of aquarium volume=> 0.28ppm of Fe.
That sounds more like it.

20 grams is a lot to try and dissolve into 500mls. I rarely make it richer than 10 grams per liter of CMS(5 grams per teaspoon average) but then I spike it with DTPA as well with another teaspoon at 10%.
You can make it whatever concentration you like. I've used a tablespoon(15 grams) per liter for a long time is all.
But it's a mix of two products.
You might try that also.

I can add however much, to get a target ppm, but I've just always used the above stock solutions of the CMS+B and have added DTPA as well.
1 ml of this would add 0.1 ppm (hold over from PMDD days) for every 100 liters of aquarium.

But there's a bit more Fe in the DTPA, about 0.15 ppm Fe per ml per 100 liters.

I add about 6-7mls per 100 liters, per day(often every other day), so this is 0.9-1.1 or so ppm per dose.

Pretty rich. About 5-7x more than PMDD suggest, also, I increased the light, CO2(2x) and the nutrients, NO3 went to 5x richer, PO4, went up 20x etc.


Regards,
Tom Barr

 

[Philosophos]

Thanks for picking up the ball for me on that one Tom, I should've realized 1g of any fert in 1L isn't going to give 6.98ppm.

20g in 500 is intense, but I haven't had any issues with precipitates using half that level along side 15-20ml of HCL in a 500ml solution.

 

[Tom Barr]

Thanks for picking up the ball for me on that one Tom, I should've realized 1g of any fert in 1L isn't going to give 6.98ppm.

20g in 500 is intense, but I haven't had any issues with precipitates using half that level along side 15-20ml of HCL in a 500ml solution.

Oh hell, I was 1/2 dead after a long run and may very well have made mistakes more than the one about 1 liter vs 1000.

Regards,
Tom Barr

 

[Gilles]

Guys; my english is not good enough to keep up with your chatter
Is my calculation correct?

 

[Gilles]

I am confused. Let's say it is possible to dillute 20 grams of 7% fe2 into 1000ml water.

Wouldn't that give me: 14000ppm?

And then;
14,000/ 1000mls/1 liters*100 liters of aquarium volume=> 1400ppm of Fe

or am i missing something?

 

[Philosophos]

it would give you 1400mg of iron in 100L, yes. But 1L of that column would contain 1.4mg of Fe, so 1.4mg/L or 1.4ppm.

Basically just knock that last *100 off your equation.

 

[Tom Barr]

20 Grams X 7% = 1/100% = 1.4 grams/Liter.
Or 1400mg/L.

That's correct.

You take 1 ml of this solution, 1 milliter..............

When you dilute this further, 1 ml is diluted into

=> 100 Liters X 1000 milliters/ 1 liter, then it's 100000x more dilute right? 1 milliter is diluted into 100liters*1000mls/1 liter = 0.014 mg/L Fe.

If you add 1 ml of 1400ppml to 999mls of DI water,. what is the concentration? 1.4ppm.

What happens if you dilute 100 times?

Now you have 0.014ppm.

Adding 10 mls would yield .14ppm of Fe.
Since you want to know how much adding 1 ml per 100 liters of aquarium, this is the correct ppm or mg/L per 1 ml with 20 grams of 7% added to 1 starting liter.
If you dosed the entire liter of 1400 mg/L into 100 liters, liters cancels then = 14 ppm of Fe.
A typical dosing per day for a CO2 enriched aquarium is about the 10mls dose for 100 liters at this mix concentration.





Regards,
Tom Barr

 

[Gilles]

Hi Tom,

This results in me having the following excel sheet:
A1 Fe concentration 0,7
A2 Grams 20
A3 Starting mls 1000
A4 Resulting ppm of starting liter 1400 (=B1*B2*100)/(1000/B3)

Question 1:
So 1ml of this sollution, per 100 liter aquarium water will give you 0.014 mg/L Fe.?

Question 2:
And you need to add approx 0,14ppm per day you say?

Question 3:
You say that you mostly don't dillute more then 10 grams per liter; meaning 5 grams per 500ml, meaning 1 gram per 100ml.If i enter this in the calculation i would get:
Fe concentration 0,7
Grams 5
Starting mls 500
Resulting ppm of stock 700
1ml per 100l adds 0,007
For .14ppm/day dose 20 mls/day

Correct?

 

[Philosophos]

I'm going to go through this one step by step. Your question is one basic to figuring out accurate DIY ferts.

First lets make 7% easier to look at. How many mg's is 7% of 1000mg?

=1000/100*7
=70

so that's 70/1000mg Fe, or

In this case we're working with 20 grams...

=20*70
=1400

That's 1400 mg in 1,000ml of solution

Now how much is in 1ml of solution?

=1400/1000
=1.4

So for every ml you add, 1.4mg of iron is added.

For 1ml in 100L the concentration would would be:

=1.4/100
=0.014

Personally I like to dose for more in the .7-1.4ppm range per week. This would mean 1ml for every L to get 1.4ppm, or half that (1ml for every 2L) for .7ppm.

 

[Tom Barr]

Hi Tom,

This results in me having the following excel sheet:
A1 Fe concentration 0,7

I think that is where the error was.

7% is 7/100 or 0.07.
Perhaps when you went from 1 ml to 1 liter an dfthen to 100 liters in the dilution of the dose.

Anyway, I'm fairly sure, based on dilutions, the 0.014ppm is correct for each 1 ml of thois added to 100 liter of aquarium.

If you wanted to target say 0.1ppm per dose of Fe, then add 30 grams of the trace mix to 1 liter.
Most of these Dry mixes tend to be fairly heavy in the other nutrients metals etc.
So you might use some DTPA Fe as well, add say 10 grams extra of DTPA Fe to this 30 grams.

This is about 10 grams at 11%.

So 10 grams X 11% or 1.1 gram per liter. Or 1100 mg/L extra Fe.
1 ml of this will add 1.1 ppm per liter.

So 1.1/100 = 0.011

So dosing 10mls will give you 0.11 extra and then you add the 0.105 from the 7% iron solution.
Total is now 0.105+ 0.11 = 0.215ppm of Fe per 10 mls per 100 liters of aquarium.

That's roughly what I add per day, you can add more/less, up to you.
Plants need much less than this, but water does things to Fe and the others that waste perhaps 80-90% of it.
So adding more often enahnces growth beyond what we think is good enough based on the plant tissue analysis, this is true more so for the metals than say N or P.

Regards,
Tom Barr

 

[yme]

0.215ppm of Fe per 10 mls per 100 liters of aquarium.

That's roughly what I add per day,

a little side step: you only use TMG as iron source? you remember that you wrote to me that extra iron on top of TMG is not really necessary.
but if so, and you add 0.2 mg/l iron just by TMG, then you add DAILY 30 ml TMG per 100 liter.

That is really really a lot....

or do you add extra iron?

greets,

yme

 

[Gilles]

@Yme: If by "You" you mean me No i don't dose TMG.

@Tom/others:
When i dilute this much Fe powder into my water, it gets blood red. Is that normal or is there also a non-colored iron powder? I mean; there is a product in the netherlands called "Ferro" by easylife which comes in 500ml bottles and adds 0.5ppm per 10ml on a 100 liter aquarium. If i want to acchieve that, i have to dilute even more powder in a bottle. How comes their solution is transparent?

 

[nipat]

Is it DTPA or EDDHA?

I used to use Fe-EDDHA 5.7%. It was VERY brownish-red, even at 0.015 PPM, turning
my tank to blackwater tank.

Later I switched to Fe-DTPA 7% (added .24 PPM daily) without color problem anymore.
The color of the solution is rust-orange. And now with much less light I've reduced the amount
further to 1/4.

I think the more concentrated Fe (higher percentage), the less color problem you get.
Because you can add less but get the same level of Fe. But some type of Fe (such as
EDDHA) has very intense color (the color of chelator perhaps?) even at very low level.

 

[Tom Barr]

@Yme: If by "You" you mean me No i don't dose TMG.

@Tom/others:
When i dilute this much Fe powder into my water, it gets blood red. Is that normal or is there also a non-colored iron powder? I mean; there is a product in the netherlands called "Ferro" by easylife which comes in 500ml bottles and adds 0.5ppm per 10ml on a 100 liter aquarium. If i want to acchieve that, i have to dilute even more powder in a bottle. How comes their solution is transparent?

Yes, it should be a nice red color. I'm not sure what all is in their product personally.
Most things like CMS+DTPA Fe etc, turn a nice red color. DTPA is often yellow.
Fe Gluconate is green/amber.

YME suggest using TMG, but adding 10mkls a day on 100 liter is plenty, but this by experience, you can add more if you wish, I doubt you would need more.
I added DTPA to TMG for some time, others' used the Fe Gluconate + TMG(Popular here in the SF Bay for a few years).

Fe Glycine is even more concentrated(20-24%), but cost more.
For the $ and for us, the ETDA, Gluconate, DTPA are the better choices.
For marine water, there's another one that works better.

Regards,
Tom Barr

 

[jonny_ftm]

Hi Tom,

Do you mean you add DTPA to CSM+B? I'm confused on how to use my CSM+B bag. Do I need any precautions about the chelators to add? Can't I use it stock?

I read more and more posts about TPN being better. I'm going to switch from TPN to CSM+B soon, because of price. Now, I'm concerned about chelators and long term results. Am I safe to move from TPN to CSM+B, do I need precautions because of different chelators? Are there any issues with CSM+B compared to TPN in the long run?

Many thanks for adding some light to these issues

 

[Tom Barr]

CMS+B is fine, just get some DTPA Fe and add about 1/4 by weight of the DTPA to the CMS+b.
This will give you something similar to TMG.

You can make it as rich, or dose more etc as TMG, that is entirely up to you and how you like to dose trace elements.

Regards,
Tom Barr