magnesium uptake in sps tank

[George]

The rate of magnesium consumption in every tank is different because of different critters we have in our tanks. IME and from reading a lot of articles and posts, magnesium depletion rate should be very slow if you keep up with regular water change with a salt that has good magnesium number.
Here is an article on magnesium from Randy HOLMES-FARLEY

http://www.advancedaquarist.com/issues/oct2003/chem.htm