chemistry and water testing question

[jgrivna]

hello all,

 

I was wondering if anyone knows how the test kits that test for calcium and magnesium work. I ask because i am considering performing my own homemade tests to save money as well as my own personal enjoyment. I know that it's possible to titrate calcium with a chelating agent such as EDTA. However, i'm concerned that EDTA will have the same affect on magnesium which is also present. So i guess that my question is this: how can I specifically titrate Mg or Ca when they are both present in a solution?

[neanderthalman]

I'm not much help. However, I have a titration test kit for ca alk and mg. If i recall correctly, there is one titration test for Ca, and then a second titration on the same sample for Mg. That might point you in the right direction.

[jgrivna]

I'm not much help. However, I have a titration test kit for ca alk and mg. If i recall correctly, there is one titration test for Ca, and then a second titration on the same sample for Mg. That might point you in the right direction.

 

thanks, I actually found the perfect resource if anyone else is interested:

 

http://www.sjsu.edu/faculty/chem55/55mgca.htm

 

it seems a little too time consuming and has a bit of a start up cost. I think I'll stick to the store bought tests.

[lakshwadeep]

EDTA may work, but you should take into account that saltwater has many other metals than just calcium/magensium.

 

I think Mr. Fosi had developed a DIY test.

 

Try searching for articles/books on marine chemistry for methods of testing.

[Tinytank]

Also consider that the high end test kits provide their ingredients on the box. Maybe something you can work with!

[Amphiprion1]

It's going to be far easier and more productive to stick to store-bought kits. It really isn't worth trying to DIY in this case.