Magnesium Conundrum - what to believe?

[brainreefspine]

Hi all,
Trouble with magnesium testing. Apex Trident reporting 1400, Red Sea test kit reporting 1600. So i bought the salifert kit and somehow it reads 1500. All of these are consistent when I repeat them multiple times. Tank seems to be thriving. Anyone have any thoughts? Am I just crazy high out of range so each test kit is saturating the first reagent or something?

 

[Garf]

Am I just crazy

Probably

 

[Coolcasino]

Hi all,
Trouble with magnesium testing. Apex Trident reporting 1400, Red Sea test kit reporting 1600. So i bought the salifert kit and somehow it reads 1500. All of these are consistent when I repeat them multiple times. Tank seems to be thriving. Anyone have any thoughts? Am I just crazy high out of range so each test kit is saturating the first reagent or something?

Are you testing at different times of the day? Are you sure you are using the test kits properly? Maybe your LFS can confirm/test for you?

 

[brainreefspine]

Testing all at the exact same time. confident I’m doing them correctly. My leading hypothesis is that the first reagent dictates the upper bound of what the manual tests are capable of detecting. 1600 is the highest value the red sea goes and 1500 is the highest value the salifert goes… that doesn’t really explain the Trident reading though. I just replaced all the Trident reagents and recalibrated it as well

 

[Randy Holmes-Farley]

FWIW, time of day has no impact on magnesium testing.

Magnesium testing is among the least accurate tests we use, and whether it is worthwhile at all is, IMO, not clear.

The Red Sea kit also seems among the most problematic for folks.