magnesium and corraline algae

[dadonoflaw]

i have recently discovered that my magnesium was at 800ppm. so i began to bring it up and noticed an increase in corraline algae growth. i know it is used by the algae so is this a normal response?

[redseasteve]

You should always try to keep your Magnesium, Calcium and Alkalinity in balance. Although its easy to become pedantic about what the levels should be, and everyone has an opinion, we generally recommend somewhere around 450ppm ca, 1300ppm Mg, 3-4 Meq/l alk. Having recently set up a MAX, I was surprised how quickly the alkalinity levels dropped due to the uptake of coralline algaes, and have been adding Coral Buff every couple of days.

[Randy Holmes-Farley]

Maintaining normal alkalinity may help coralline algae yes, but I'm somewhat skeptical that yours really was that low.

What salt mix are you using, and have you tried measuring magnesium in it to check the kit?