Hi Reefer Rob,
If you are in a bind, I know that Univar Canada in Calgary can get you both the Dow and Mag Flakes.
This link may be of assistance:
http://www.univarcanada.com/manufact...specialist.htm
You have two contacts in Vancouver
.
To complete the 3 part magnesium, go to the local drug store and buy yourself a jug of Epsom salt, I use the Rexall brand. The Mag flakes will last a very long time
.
Good luck