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dodgy67 · 03/08/2020, 04:40 AM

This was the original thread I was following
Following this recipe by @Randy Holmes-Farley

Manganese(II) chloride tetrahydrate is 28% manganese by weight.
Here's a recipe:

Dissolve 1 gram in 100o mL (grams) fresh water. Manganese = 280 ppm.
Take 1 mL (1 g) of that mix and dissolve in 1000 mL of fresh water. Mn = 0.28 ppm (=280 ug/L).
Add 1 mL of that to 100 mL of fresh water. Mn = 2.8 ug/L
Add 13.5 mL of that to 100 gallons of tank water. Conc boost to tank = 0.1 ug/L Mn.

To me the 0.1ug/L did not look right as seawater in 0.01ppm which is 10ug/L

Please correct me if i'm wrong but this is my calculation
Dissolve 1 gram in 1000 mL (grams) fresh water. Manganese = 280 ppm = 280,000ug/L

Take 1 mL (1 g) of that mix and dissolve in 1000 mL of fresh water. Mn = 0.28 ppm (=280 ug/L).
Therefore if my tank is 350L dosing 1ml would be 0.8ug/l so to get 10ug/L (0.01ppm) would require 13ml which I would dose in 1ml increments to be safe.

Doesn't appear there is a Manganese test kit around type in Manganese and you get Magnesium.

Thanks very much for your reply

03/08/2020, 04:40 AM	#3
dodgy67 Dave Join Date: Dec 2014 Location: Leighton Buzzard UK Posts: 122	This was the original thread I was following Following this recipe by @Randy Holmes-Farley Manganese(II) chloride tetrahydrate is 28% manganese by weight. Here's a recipe: Dissolve 1 gram in 100o mL (grams) fresh water. Manganese = 280 ppm. Take 1 mL (1 g) of that mix and dissolve in 1000 mL of fresh water. Mn = 0.28 ppm (=280 ug/L). Add 1 mL of that to 100 mL of fresh water. Mn = 2.8 ug/L Add 13.5 mL of that to 100 gallons of tank water. Conc boost to tank = 0.1 ug/L Mn. To me the 0.1ug/L did not look right as seawater in 0.01ppm which is 10ug/L Please correct me if i'm wrong but this is my calculation Dissolve 1 gram in 1000 mL (grams) fresh water. Manganese = 280 ppm = 280,000ug/L Take 1 mL (1 g) of that mix and dissolve in 1000 mL of fresh water. Mn = 0.28 ppm (=280 ug/L). Therefore if my tank is 350L dosing 1ml would be 0.8ug/l so to get 10ug/L (0.01ppm) would require 13ml which I would dose in 1ml increments to be safe. Doesn't appear there is a Manganese test kit around type in Manganese and you get Magnesium. Thanks very much for your reply __________________ Dave 3 years still lots to learn about reefing Mag Curve 5 Skimmer, Jebao 4 way dosing pump,4 way slave, Maxspect Gyre 2 x XF230 T5 4x39w 2xBlue 1xBlue Plus 1xPurple Mixed SPS & LPS Current Tank Info: Red Sea Max C130. Self built 44x19x19 tank and stand June 2016 Maroon Clowns , 2 Pajamas, Sand sifting Goby, mixture of SPS and LPS