[p.cubensis]

before i start, i want to say this is for research purposes only.

THC (which is the chemical in marijuana that causes euphoria and is what drug tests test for) is a VERY non polar chemical and the molecule is very large and bulky so it should be easily attractejd to and filtured out by activated carbon...

what i was wondering is that if you had an activated carbon filter and urinated through it would it filter out enough thc to make a drug test negative... even if you had to filter the same urine multiple times would it either filter out enough to pass or filter it out completely

[Arkcon]

I'm sure that could be tested very easily by the drug test makers.  You seem to have provided the procedure perfectly.  It might be interesting enough to publish, if it worked, but I doubt anyone publishes a "everything's working fine" paper, they would just mention in their advertisement blurb "confirmed determination of positive result even if triple activated carbon filtered."  Should be easy enough to test for ... uh ... research purposes.   Find someone who failed a test and try it.  Somebody fails these tests at some time, you don't have to ... secure someone to test it out for you.  'Cause , you know, no one would want to do that.   

[p.cubensis]

i like the answer but id like more of a "yes this will or work or no this wont work and why" answer

[Honclbrif]

i like the answer but id like more of a "yes this will or work or no this wont work and why" answer

Sounds like you've graduated to PI already.

/Just pee through the goddamn Britta filter already. Seriously, you don't even have to tell your roommate.

[Fluorine]

1. Which test? The NIDA 5 or something more specific? I would be surprised if anyone can give you "yes" or "no" response without any information of the urine test type.

2. THC is quite non-polar however you've neglected to consider the pharmacokinetic results of it's presence in the body. Enzymes will make it more polar to help it leave the body. Some of these metabolites are quite polar (THC metabolites (wikipedia)) relative to the parent. Will these metabolites be stopped by a carbon filter? If so, will it be the ones a test kit detects? Again, if so, will the concentration be low enough to evade the cut off point for detection?

3. What about non-THC cannibinoids in Cannabis spp. - are any of these detected by the urine tests? Their metabolites?

There are many variables you're wishfully ignoring. You can find a bit of starter information here.