DIY Manganese - Calculation Help

[Japtastic]

So I have undetectable Manganese in my tank from my latest ICP.

I have the ingredients but my maths is shocking and I don't want to get this wrong.

I'd like to bring the value up to 0.9 ug/l or 1.0 ug/l if it won't harm the tank. 0.88 is the value listed to aim for...

Tank volume is 350 US Gallons

What I'd like to do is skip the last dilution to the 100ml part if possible and dose straight from the 1000ml 280 ug/l bottle.

Thanks

Edit: Is it 4.25ml ?

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.

 

[Japtastic]

Anyone? Would like to dose this soonish.... Thanks

 

[JimWelsh]

To target 0.88 ug/L in 350 gallons, use 4.16 mL of the 280 ug/L bottle.

 

[Japtastic]

My 4.25ml calculation for 0.9 seems correct then. Cheers for the confirmation.

 

[Randy Holmes-Farley]

Here's my comment on the none detected from my Triton testing article:

Manganese (Mn). Triton can just barely detect the natural level of manganese (0.17 µg/L) since their LOD is 0.12 µg/L. Detecting none suggests it may be depleted, and is another possibility for dosing, but I have less confidence that this one is really seriously depleted since it is so close to the LOD. But Mn is biologically important and I will consider it.

 

[Japtastic]

Thanks for your comments, Randy. My tank is fairly new. I have dosed the MN and will see if it’s being used up by the Chaeto when I next send another ICP test off.

 

[Randy Holmes-Farley]

Thanks for your comments, Randy. My tank is fairly new. I have dosed the MN and will see if it’s being used up by the Chaeto when I next send another ICP test off.

Mn is consumed very fast by macroalgae and it is a fine additive to experiment with.

 

[Japtastic]

Thanks, are there any concerns on higher amounts being in the tank if I continue to dose some and it's not used up over the next few weeks until I do another ICP?

 

[Randy Holmes-Farley]

Thanks, are there any concerns on higher amounts being in the tank if I continue to dose some and it's not used up over the next few weeks until I do another ICP?

It's likely fine. Even a little macroalgae growth can strip the tank of manganese.

 

[Tmmste]

Thanks, are there any concerns on higher amounts being in the tank if I continue to dose some and it's not used up over the next few weeks until I do another ICP?

I overdosed once, 300x nsw. Apart from a massive cyno outbrake, no losses.

 

[Joe Rice]

To target 0.88 ug/L in 350 gallons, use 4.16 mL of the 280 ug/L bottle.

I'm confused.

350 gallons = 1325 L

0.88 ug/L * 1325 L = 1166 ug

1166 ug / ( 280 ug/L) = 4.16 L (not mL)

Am I doing something wrong?

 

[JimWelsh]

Am I doing something wrong?

Hmmm. Apparently not.

 

[Japtastic]

I'm confused also. Even if I used the original recipe for my tank (350 gallons) aiming for 1.0 ug/l my workings were as follows.

Add 13.5 mL of that to 100 gallons of tank water. Conc boost to tank = 0.1 ug/L Mn.

13.5ml * 3.5 = 47.25ml * 10 = 472.5ml

 

[Joe Rice]

In fact, I believe the 13.5 ml for 100 gallon should be 13.5 L. which would mean you would actually need to add 472 L (!!) of the 2.8 ug/L solution to raise 350 gallons 1.0 ug/L (@Randy Holmes-Farley)

100 gallons = 379 L

0.1 ug/L * 379 L = 37.9 ug

37.9 ug / (2.8 ug/L) = 13.5 L (not mL)

 

[Hitman]

There is 1000 ml to 1 L and 3.78541 L per gallon, so your saying he would have to dose 3.566323 gallons! That's a lot! There must be a equation error somewhere and I'm definitely not the smart one to know where. Just thought I'd point out the ML to L to US gallons conversion.

 

[Joe Rice]

There is 1000 ml to 1 L and 3.78541 L per gallon, so your saying he would have to dose 3.566323 gallons! That's a lot! There must be a equation error somewhere and I'm definitely not the smart one to know where. Just thought I'd point out the ML to L to US gallons conversion.

Of course, these numbers are impractical. I'm thinking one might want to aim for creating a dosing solution at 2800 ug/L or even 28,000 ug/L rather than 2.8 ug/L

 

[Japtastic]

Hmm ok. So what is the correct way to achieve what I need? I still have plenty of Magnese Chloride Tetrahydrate.

 

[Joe Rice]

Hmm ok. So what is the correct way to achieve what I need? I still have plenty of Magnese Chloride Tetrahydrate.

Wait until @Randy Holmes-Farley replies. I'm still nervous that I've made a mistake.

 

[JimWelsh]

@Japtastic and I both made the off-by-1000 error that @Zirco called out, and @Randy Holmes-Farley didn't catch it. My original answer of 4.16 mL would be correct if you were using the first with 280 ppm Mn, instead of the second one that was diluted by 1000 to 280 ug/L.

 

[Japtastic]

@Japtastic and I both made the off-by-1000 error that @Zirco called out, and @Randy Holmes-Farley didn't catch it. My original answer of 4.16 mL would be correct if you were using the first with 280 ppm Mn, instead of the second one that was diluted by 1000 to 280 ug/L.

Thanks Jim, I think I see what you mean. Can you confirm?

Can I just follow the first step here:

Dissolve 1 gram in 100o mL (grams) fresh water. Manganese = 280 ppm.

Then to target 0.88 ug/L in 350 US gallons, use 4.16 mL?