Posted by bluedog on April 11, 2003, at 21:38:13
In reply to Re: Is my Maths correct?, posted by Larry Hoover on April 11, 2003, at 14:10:27
> > > Yes, but....how do you propose to measure out 62.5 mg?
> > >
> > Good point, I just checked out my kitchen scales and it would be rather difficult to measure out 62.5mg accurately. However doubling the amount to 125mg would be easier to measure out give or take a few grams but effectively doubling the strength of each 20ml dose to 300mg elemental Mg.
> You could also divide the 500 mg in half by volume. Just measure the whole thing in cups or whatever, and mix half of it with one litre of water. That would make 5 mL (one teaspoon) equal to 150 mg Mg.
Very good suggestion Larry!!!!!
> > I can see your point, it would probably be a lot easier to buy a really cheap measuring cup with more graduations including 2.5ml, 5ml, 10ml etc to make things a little easier for me, or one of those sucky thingy's (I don't even know what you call them) with 0.5ml graduations) and to dissolve the whole 500g tub of my Mag Chlor into one litre of water.....Right?????
> It's the simplest thing to do, all things considered.
> > I did use a calculator but I initially had completely forgotton how to re-arrange equations but once I practiced a bit it all came back to me and I finally got there and this is the equation I came up with working with my limited measuring ability of only a 20ml measuring cup:-
> > Xml=(60g)(20ml)/0.15
> To be rigorous, there would need to be a g after the 0.15.
Touche....now were even:):)
> > So all in all your original equation ends up being a lot more helpful to me:) :). In other words
> > Xml = (1000ml)(0.5)/60g
> Again, just for the people following along at home, there needs to be a "g" alongside the 0.5.
Just rub it in why don't you :):):). Be aware I'm now on the lookout for any of your mistakes Larry ;).
> > but I have simply replaced the 0.5 you used as an example with my target strength of 0.15 to get my intended dose of 150mg of elemental Mg per dose. You only need vary the 0.5 to 0.15 or 0.3 or 0.5 etc to get the ml you require for a particular dose strength of elemental Mg.
> That's exactly right. You answer the question: "How much volume of this solution do I need to supply a given mass of Mg?"
> > And applying this equation 2.5ml of the whole 500g tub dissolved in one litre does indeed give me a 150mg dose of elemental Mg (give or take a few mg either way due to my equipment not being lab quality accuracy) but it's good enough for my purposes. I can't argue with the experts:) :).
> You're welcome. You might want to consider the alternative I mentioned at the top.....divide the volume in half, and mix one of those halves into one litre. That gives you a more manageable volume/mass relationship of 5 mL to 150 mg Mg.
Like I said above....great idea Larry.....Also it's dead easy to measure out 250g on my kitchen scale.
Thanks once more Larry. Your an absolute gold-mine on this board!!!!