yah i added the cyrstals 6 hours before the piss test. Sucks though keep worrying about it, but i cant find any canadian posters saying they ever failed using it. Kinda funny how canadian drug testing companies do more stringent tests, and were supposed to be the more relaxed of the two countries when it comes to drug. All the other tests iv had in Alberta were dipstick tests, and could pass them with just flushing.They would do the test right there infront of you. This one was put into two cups and sealed, so i can only guess if there just going to dipstick it later or do something more serious.