just be careful....like i mentioned before, using mail or couriers is not the best way...people have been burned before.......especially if you label it one thing and customs inspects it and finds something else...you will be fined....trust me.
and don't think labeling it 'crushed live-rock, or dead coral skeleton, etc will do the trick....those customs peeps are fairly well trained (unless they had a bender the night before and are too hung over to care lol!)
the best way to trade, IME, is to bring it on your person when you visit....either by driving or flying across..that way you can back it up if there are probs.
who told you that it's OK to ship from the US to Canada via UPS?.....I have a feeling I know exactly who it is......tell him Patwa says he's 100% wrong.....you cannot legally ship goods that are considered "alive" across international borders, unless you have permits/documention, etc.
Zach