I agree with the water thing. I had to take a piss test for work and I found out about it the day before I took it. I wasn't worried about it, cause it's just a job and I can find another one. So I drink a couple gallons of water that night and some in the morning before the test. Took the test. Smoked on the way home. They call me a few days later and say I am hired. Guess the water did the trick...and by the looks of it...my piss was ALL water lol.