Salifert Mg kit turning bad?

[disaster999]

so i havent tested Mg in a while since my old bucket of reef crystals had the right amount of Mg and it was pretty constant. well i depleted my bucket and got a new one. did a few test to make sure everything checks out and Mg is pretty low (<1200ppm). went and got brightwell Mg to bump my levels back up so ive been using it almost everyday. i noticed that the colors durning the Mg test were not as pale when i first got it. when combining solution 1 and 2, i usually get a pale pink color, but mine is a pretty dark pink when i do my titration, the solution turns to a dark blue instead of the pale blue ive seen before.

 

the reason im asking this is because according to brightwell, 1ml of Mg solution adds 26ppm per 1gal of water. i have an around 22gal system. my initial level when i first tested with my kit 1140ppm so i would need around 135ml to bump my levels to 1300ppm. i only added 80ml and i already reached the 1300ppm mark. so im thinking either brightwell under claimed their dose, or my kit is bad

[pprwngs]

My Salifert Mg test is the same way, a really deep dark pink and then turns to a gray-blue color. And I have noticed the understating from Brightwell too. I wonder which is wrong? And I really don't feel like buying more test kits.

[disaster999]

thanks, good to know its not just my test kit