# Does Magnesium add a secondary chemical?



## AverageWhiteBloke (2 Jan 2021)

Talking Epsom salts here. Can't help but notice that you have to add a fair amount of Epsom to yield a relatively small ppm of Mg. Is there something else being added to the tank or is it purely about the size of the crystals? What exactly is the sulphate?


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## dw1305 (2 Jan 2021)

Hi all,


AverageWhiteBloke said:


> a fair amount of Epsom to yield a relatively small ppm of Mg


Yes, it is just down the Relative Molecular Mass (RMM) of the compound, in this case = 246.47 g/mol, which means that there is only ~10% magnesium (RAM 24.3).


AverageWhiteBloke said:


> Is there something else being added to the tank or is it purely about the size of the crystals?


There is a lot of water, because of the <"water of crystallization">. It is the "7H2O" part of MgSO4.7H2O, which makes "Epsom Salts" <"the "heptahydrate">.


AverageWhiteBloke said:


> What exactly is the sulphate?


Magnesium sulphate is a "salt", which means it was formed from the reaction of an acid and a base, so in this case we know that the acid is <"sulphuric acid"> (H2SO4) and the base was probably magnesium carbonate (MgCO3).

"Epsom Salts" go into solution as an anion (SO4--) and a cation (Mg++) and also some H2O.

cheers Darrel


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## MrClockOff (2 Jan 2021)

I love your chemistry knowledge! I wish I was paying more attention during my chemistry classes back at school..


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## AverageWhiteBloke (2 Jan 2021)

Cheers Darrell. 



MrClockOff said:


> wish I was paying more attention during my chemistry classes back at school..


School is really over rated mate, you just need to knock about in this forum for a bit. 
I was "asked to leave" school when I was 15 for being too cool for my teachers liking and left with nothing more than a swimming certificate and cycling proficiency. Now because of this forum I find my self helping my daughter with her level 3 applied sciences revision from college. 
But hey, if you ever need a rubber brick retrieved from the bottom of a swimming pool by somebody wearing pyjamas I'm your man. Over qualified if anything.


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## Zeus. (2 Jan 2021)

We do have four main choices for Mg and all add secondary cations




All of then need approximately the same mass for the same Mg ppm gain except the carbonate
as for their cost for the same Mg ppm yield






Tf your concerned about your sulphate levels using magnesium chloride hydrate in a 50:50 mix is as cost effective, with an increase in the Cl ppm
*
*


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## dw1305 (2 Jan 2021)

Hi all,


MrClockOff said:


> I wish I was paying more attention during my chemistry classes back at school.


I don't actually know much chemistry. I've just the bits I've picked up at work and on the forum. If I have a technical question I have to ask <"some-one who knows"> and can explain it to me in terms <"I can understand">. If you want an analogy I can change the wheels on a car, but I can't diagnose the engine management system.  


AverageWhiteBloke said:


> Now because of this forum I find my self helping my daughter with her level 3 applied sciences revision from college.


Brilliant, however I bet if they put "planted tank fish keeping" on the school curriculum they could suck all the joy out of it like a <"turbo-charged Dementer">.

cheers Darrel


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## AverageWhiteBloke (2 Jan 2021)

dw1305 said:


> put "planted tank fish keeping" on the school curriculum


That's where they went wrong with me mate. They should have showed me the tank first then I might have been interested in what else they had to say. 
I often find myself working in schools refurbing during the holidays. Sometimes I look at all the equipment and think if I had my chance again. Better late than never I suppose. 

I found myself at Christmas explaining to someone who works in a chemistry lab in a nuclear plant how energy and mass works and can't be destroyed or created in a vacuum using a house plant as an example (obviously fuelled on alcohol) she couldn't give a sh@t. Clocks in, tests the samples, takes her pay check.

I suppose you need to apply science to something interesting to make you want to know. Must be hard for the teachers to get people interested. With the exception of my physics teacher who kept you interested with a metre long metal ruler called "Excalibur" oh the good old days.


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## dw1305 (2 Jan 2021)

Hi all,


AverageWhiteBloke said:


> Must be hard for the teachers to get people interested.


I could never be a teacher, <"my wife is">, but it would drive me mad. I didn't have a great experience of school (went to a <"comprehensive school in the country"> and nobody wanted to be there, (pupils, their parents, or the teachers), and it would be fair to say I was pretty demotivated from early on.


AverageWhiteBloke said:


> I found myself at Christmas explaining to someone who works in a chemistry lab in a nuclear plant how energy and mass works and can't be destroyed or created in a vacuum using a house plant as an example (obviously fuelled on alcohol) she couldn't give a sh@t. Clocks in, tests the samples, takes her pay check.


You find the same in Universities, most people are incredibly invested in their work, but often don't have time for, or interest in, what anyone else does. It always amazes me, but I suppose our education system encourages people to specialize from an early age and rewards those who can learn in a linear manner and don't ask too many questions

cheers Darrel


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## sparkyweasel (2 Jan 2021)

AverageWhiteBloke said:


> a swimming certificate and cycling proficiency.


You could go a long way.


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## AverageWhiteBloke (2 Jan 2021)

dw1305 said:


> encourages people to specialize from an early age and rewards those who can learn in a linear manner and don't ask too many questions


Was my point mate, she was a straight A student, got lots qualifications but her main motivation was getting a job at the best paying employer round these parts. Her interest in science began and ended with the paycheck. 
I would do her job for half the money and be a lot keener, I certainly wouldn't have forgot the basic laws of physics yet. I question everything which is probably why I haven't got her job, I would imagine it's the type of job where asking questions would make you a trouble maker. 
Maybe that's what went wrong at school, I asked too many questions and eventually asked the question why do I bother coming here anymore 😂 These days they would probably say I was on the spectrum for asking why and when all the time. 
Still, one day there will be a vital piece of equipment in one of cooling ponds on that nuclear site and I'll be there in my pyjamas mate looking smug. I go down on my bike so they get the full benefit of my area of expertise.


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## brhau (2 Jan 2021)

I left my first job to go back to school at age 30 to learn science. It was very clear in my second go at University that our education system selects for obedience, not for learning. Ironically, it's the disobedient students who tend to be more creative thinkers, which is needed to be a good scientist. So you see a fair number of successful scientists who had bad grades through college, but just good enough to get into graduate school, where grades are no longer of consequence.

In the States, the career path to becoming a medical doctor selects for high grades throughout, so I had a LOT of classmates who were solely motivated by the prestige of being a doctor. They tended to be completely uninterested in the science (as evidenced by a majority of them thinking that organic chemistry was a "hard" class). I fear the day I awake in a hospital bed to see one of their faces.


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## AverageWhiteBloke (2 Jan 2021)

brhau said:


> I left my first job to go back to school at age 30


One of my biggest regrets mate. To be fair life's been pretty good to me. My teenage angst didn't decide the rest of my life, I've spent the last 25 years running my own business after doing a few jobs I wasn't too happy with. Given the chance I would probably have done that but running the business and family had to come first. I find poverty is a great motivator. 
It was something I was seriously considering this year when I hit 50 before it was way too late in life but the small matter of a global pandemic put paid to that. 
You never know though, stranger things have happened.


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## AverageWhiteBloke (3 Jan 2021)

Zeus. said:


> We do have four main choices for Mg and all add secondary cations


You'll have to excuse my ignorance here, I have been trying to get to grips with the IFC calculator as I'm sure there isn't any question it can't answer regarding chemicals and dosing. I think it may be user error more than anything and the fact that I tend to revive old hardware with Linux OS so I'm stuck with Libre office using ods files as its default so perhaps there may be some things lost in the formatting of excel files. I always use James planted tank as my goto calculator although to be fair something I've always used as a rule of thumb when dosing Mg knowing it isn't that important is that when dealing with 100ltrs 1gram of mgs04 tends to raise the ppm of mg by roughly 1ppm. Where on your graphic there does it say that mate?





The way I'm reading yours its says 16.84 grams raises to 5ppm no?


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## AverageWhiteBloke (3 Jan 2021)

I'm guessing I use the 5 from here and here. Just not sure what the 16.84 grams bit means?


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## Zeus. (3 Jan 2021)

The 16.84gr is the total mass off all four salts
Only have one salt and..



There is also a picking/targeting order when going working from ppm to grams. So each salt had to be given its prime/targeting element/compound. So for MgNO3 it was NO3, for MgCl and MgSO4 is was Mg and MgCO3 it was CO3

so to get an even mix of all four Mg salts I had to play with different target element/compounds




So it does take a little getting use to, plus you can always use the DIY calculator as that does gram to ppm

The target calculator had to have a picking/targeting order and you can get it so the target is over shot depending on which salts you use. Try making a TSN clone with KNO3 - its not possible without using ammonium compounds


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