WTB Magnesium and Calcium
 

is there someone i could ask to buy this from in Lower mainland? or should i look online? as for alkalinity how would i adjust the alk in instant ocean to about 10dkh at a sp. gr. of 1.023 ( i dont need to know how actually, more like what should i add to the mix to raise alk? what chemical?)

you have pm

Here is a calculator for how much you would need to add.

http://home.comcast.net/~jdieck1/chemcalc.html