Thx. I just ordered from ebay, a USA supplier who apparently will ship to Canada. Price was about $12 a foot, but has since gone up to 13 or 14. It is 99.99 pure, but who knows, no way to check that. According to articles i've read, 99.99 is ten time more pure than 99.9. You could be right in that it may not actually make any difference in the end. I am just happy that i will be able to make my own supply of cs, so i can be more generous with it. At the cost of $27 per 500ml, one has to be somewhat conservative.