Magnesium test??

[JAWSIII]

Hi , I am using salifert test for mag, cal, dkh and phosphate. When doing my latest round of tests I noticed something on the Mag sheet that stated “calcium levels between 300-500ppm should not interfere with results”. My calcium tests at 540ppm. My mag has been testing off the chart 1500 plus. I even used a second syringe full and calculated that the mag was at 1600. My LFS API aqua spin test showed the mag was at 1280. I’m not so concerned with the actual number but more is the higher calcium skued the mag reading.

is there any way to “subtract” a value off of the mag reading if the calcium is above 500 ? Or is this not really a concern? I fell like mag at anyone of those levels is ok. I just wanna keep it stable and use a baseline number.
Thanks.

 

[vetteguy53081]

Safe CA level is about 440
I would suggest both an ICP test and taking a water sample to a trusted LFS that does not use api test and see what results they come up with and to compare with other two and you will then know what you actually have

 

[Randy Holmes-Farley Verified Community Expert]

I do not think there's a concern that a calcium level of 540 ppm is causing magnesium to read much higher than it really is. Simple subtraction is not appropriate.

 

[ChaosAquaculture]

your calcium should generally be in the 400-460 range. With calcium of 540, depending on what your alkalinity is your magnesium test is most likely correct. What is your alkalinity at currently? = kali

 

[JAWSIII]

Currently all is at 9.5

 

[rusgum]

Hi , I am using salifert test for mag, cal, dkh and phosphate. When doing my latest round of tests I noticed something on the Mag sheet that stated “calcium levels between 300-500ppm should not interfere with results”. My calcium tests at 540ppm. My mag has been testing off the chart 1500 plus. I even used a second syringe full and calculated that the mag was at 1600. My LFS API aqua spin test showed the mag was at 1280. I’m not so concerned with the actual number but more is the higher calcium skued the mag reading.

is there any way to “subtract” a value off of the mag reading if the calcium is above 500 ? Or is this not really a concern? I fell like mag at anyone of those levels is ok. I just wanna keep it stable and use a baseline number.
Thanks.

I would first check your tests with a reference liquid, because the magnesium and calcium test can deviate up to 100 units