Calculating Ca

[DC634]

Is there a way to calculate the levels of Calcium and Magnesium given results for KH and GH?

KH: 4 dKH
GH: 12 dGH

If not, what is the best way to get these numbers?

[BBradbury]

Hello DC...

If you want the specific numbers for the mineral content of your water, you can check with a few places. Your local water department will have it. Some pet stores have the means to give you those numbers, as will your local high school chemistry departments. Take your pick.

B

[ZxC]

Yes there is:

API Ca test kit can detect 0, 5, 10, 15, 20, … ppm Ca.

Get 20 ml of aquarium water, add 5 drops of #1 solution and mix.
Start adding 1 drop of #2 solution and mix and watch for colour change from pink to blue. Each drop of #2 solution equals to 5 ppm Ca.

How do I test for Mg?
First test for GH and Ca, then calculate Mg.
Mg testing
((17.86 x dGH) - (2.5 x Ca ppm)) / 4.1 = Mg ppm
(ppm dGH - (2.5 x Ca ppm)) /4.1 = Mg ppm

[DC634]

I am not looking at water straight from the tap so the city treatment plant would not be the ideal place to go. I was more wondering if there is some kind of formula I could use on a regular basis to calculate them when I test my KH and GH parameters.

[DC634]

So in other words I need to purchase a Ca testing kit. Then from there I could calculate Mg.

Thanks

[ZxC]

Originally Posted by DC634

So in other words I need to purchase a Ca testing kit. Then from there I could calculate Mg.

Thanks

Yes that is how it's done.

Total gH - Calcium's contribution to gH = Magnesium gH.

[DC634]

Alright, thanks. I will order one when I get home.