Magnesium magically stable (and high)

[lastlight]

I haven't dosed mag to the tank since the transfer. I dose roughly 250mL of Ca/Alk per day.

I thought my Elos kit was off with a 1500 reading yesterday so I cracked into a new one and got the same thing! How is this possible?

Not sure it's related but coral growth is great and most of my coraline has died. New coraline forms on the glass extremely slowly.