MgCl - anhydrous vs hexahydrate

[punchy]

i'm trying to make randy's 2 part magnesium first recipe, per
http://www.reefkeeping.com/issues/2006-02/rhf/#12

which calls for 3:5 magnesium chloride hexahydrate to magnesium sulfate. unfortunately i picked up magnesium chloride anhydrous for some reason.

what are the portions for anhydrous to achieve the same thing?

thanks in advance!

[punchy]

oops link should be ../#6, not #12

[bertoni]

Do you have a scale? The weight should be about half that of the hexahydrate.

[punchy]

Do you have a scale? The weight should be about half that of the hexahydrate.

thank you!

i'm guessing that's from

Molar mass
95.211 g/mol (anhydrous)
203.31 g/mol (hexahydrate)

my highschool chem teacher is frowning at me right now

[bertoni]

Those numbers are correct. :) I don't know how to predict the volume.