Dosing Fe & Mn recommandations

Tmmste · Mar 28, 2018

Today I received Mn-EDTA. it is 6%.. but is this by volume or weight?... 1 liter weighs 1.34 kG.. would it be 6 grams or 8.04 grams?

Apart from that.. it will be pretty concentrated stuff.. if it is by weight it wil contain 8040ppm. 1 drop is 0.38ppm (1/21 of a ml.. 1000ml is a bottle). so for my 400l tank.. 1 drop is 9ppb right? that is almost 5x the recommended amount..

If someone can confirm this, thank you!

Tmmste · Mar 28, 2018

Tmmste said:
Today I received Mn-EDTA. it is 6%.. but is this by volume or weight?... 1 liter weighs 1.34 kG.. would it be 6 grams or 8.04 grams?

Apart from that.. it will be pretty concentrated stuff.. if it is by weight it wil contain 8040ppm. 1 drop is 0.38ppm (1/21 of a ml.. 1000ml is a bottle). so for my 400l tank.. 1 drop is 9ppb right? that is almost 5x the recommended amount..

If someone can confirm this, thank you!

I mean 0.9 ppb.

Randy Holmes-Farley · Mar 28, 2018

If you have a solid dissolved in a liquid, % really can’t be anything except weight percent. 6 wt % = 60,000 ppm.

Randy Holmes-Farley · Mar 28, 2018

You weighed 1 liter of this material to be 1.34 kg?

Tmmste · Mar 29, 2018

Randy Holmes-Farley said:
You weighed 1 liter of this material to be 1.34 kg?

It is stated on the bottle, see attachment. I think I heavily overdosed with 1 drop:

.. 0,06 x 1340 grams = 80,4 gr manganese. Is 80400 ppm. So 1 drop is 80400 / 21000 = 3,83 ppm!... for my 400l tank.. that would be a rise of 3,83 / 400 = 9,57 ppb. that is.. way to much.
So I cross my fingers the ATS will absorb some Mn... tank still looked good this morning... dosed it yesterday in the afternoon... and hope to dodge a tank crash.

Randy Holmes-Farley · Mar 29, 2018

Where does the 6% number come from?

Tmmste · Mar 29, 2018

Randy Holmes-Farley said:
Where does the 6% number come from?

https://www.deoplosmiddelspecialist.nl/kopen/Mangaanchelaat-EDTA-6

Schermafbeelding 2018-03-29 om 16.49.11.png

Randy Holmes-Farley · Mar 29, 2018

FWIW, I can't tell if that product is 6% manganese or 6% manganese EDTA = 1 % manganese by weight.

Randy Holmes-Farley · Mar 29, 2018

If the weight of 1l is accurate, it can’t be just 6% manganese edta. Would have to have 6% Mn, or something else also in it.

Tmmste · Mar 30, 2018

Randy Holmes-Farley said:
If the weight of 1l is accurate, it can’t be just 6% manganese edta. Would have to have 6% Mn, or something else also in it.

I asked for more information, but still can't tell as far as I can see.

zachtos · Sep 22, 2018

For calculation of fergon, please correct me if wrong:
55.8 g/mol Fe / 448.156 g/mol (fergon) = 12.4% by weight iron?

27mg / 100g * 1g / 1000mg = 0.00027 * 12.4% = 0.00003348 or 33.5ppm solution

now raise 0.1ug/L

33.5ppm x mL = 0.1ug/L x 100 gallon x 3.785L / gallon
x mL = 37.85 / 33.5
1.13 mL raises 100 gallon of water by 0.1ug (micro gram)

Randy Holmes-Farley · Sep 22, 2018

zachtos said:
For calculation of fergon, please correct me if wrong:
55.8 g/mol Fe / 448.156 g/mol (fergon) = 12.4% by weight iron?

27mg / 100g * 1g / 1000mg = 0.00027 * 12.4% = 0.00003348 or 33.5ppm solution

now raise 0.1ug/L

33.5ppm x mL = 0.1ug/L x 100 gallon x 3.785L / gallon
x mL = 37.85 / 33.5
1.13 mL raises 100 gallon of water by 0.1ug (micro gram)

The first line of calculations is not needed or useful.

Also, no hobby-available test can detect natural levels, so one just needs to pick a dose and use it. Not sure how you selected 0.1 ug/L, but that is likely OK. I personally dosed typically to 1-2 ug/L once or twice a week. Iron dose is really not very important. It's way higher than typical surface NSW levels in either case.

One Fergon tablet contains 27 mg of iron. Dissolve that in about 27 mL RO/DI (my recommendation, but other concentrations are OK, just don't dilute too much), the concentration is about 27 mg/27 ml ~ 1 mg/mL.

If you want to dose to 0.1 ug/l (0.0001 mg/L), then you need to dose 1 mL per 10,000 liters of aquarium water.

I dose 10-20 times as much (~1 mL to my tank with a volume of about 300 gallons ).