I want to keep smoking weed. I have to pass the drug test though.

[Doc7]

Supposedly drinking water for the entire morning of your drug test (I am talking almost to the point of that thing where your brain swells and you die) will let you piss almost pure water with untraceable amounts of weed, if you haven't smoked for at least a a couple weeks.

if you can't lay off for a couple weeks, you might want to seek therapy.
edit: From the OP, sounds like you will have no problem doing this.

edit 2: I know a person who was found with weed in the trunk of his car who did this. So my post should not actually read "supposedly", it actually happened. I believe he was drinking out of a cup of water continously for 4-5 hours.