12.5 micromol Fe2 to ppm?

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

 

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

 

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

 

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

 

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

 

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

 

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