Aquaforest reef salt parameters way off

[Velcro]

So I haven't checked my Magnesium in my new tank since I just went through about 100 gallons of my 22kg bucket. Today I tested my mg with a Nyos kit. 1800ppm

Huh, that's weird. Lemme double check with my salifert kit. 1725ish ppm.

What the...

So I make up a fresh 10 gallons with the salt which is getting towards the bottom of the bucket. I'm mixing it to 35 ppt, which is what my tank is currently at. I'm testing salinity with a red sea refractometer calibrated before EACH use with 35 ppt solution. I've also got a calibrated apex conductivity showing the same salinity in the fresh mix as well as the tank as it sits.

I test the fresh 10 gallons of aquaforest reef salt. 1750 ppm.

This led me to testing Ca and dKH as well.
Ca- 375ppm (red sea)
dKH- 7.2 (hanna)

So Mg is way high, calcium is low compared to what is stated on the website. Is this a known issue?

 

[Velcro]

Never mind! I was using the same vial for all these magnesium tests, and decided to do a vinegar soak then try again. Both fresh made saltwater and my tank are much closer to the 1500-1600 I'd expect