Need help with Salifert Magnesium test.

[Reef Devils]

I’ve been having a lot of trouble testing my magnesium. I’ve had tests that say It’s too high of other tests say it’s too low. You guys suggested me to get the Salifert Mafneaium test. I wanna make sure I get the most accurate test. It says add MG- Reagent into the test vial until the condition lot changes to gray or blue. As I’m adding it in the color, turns purple then blue. When it turns purple should I stop? Or whenever just starts changing color does it mean I should stop?

 

[blaxsun]

When it turns blue wait 10-15 seconds. If it defaults back to purple add another drop and repeat until it stays blue.