Drug tests for employment you can get away with sneaking clean urine in.
Drug tests for probation you generally can't - they will watch you.
Depending on the type of offense and what they are testing for you will face a different test. They are most likely administering a general urine test for the 5 main drugs, the "SAMHSA 5".
marijuana, cocaine, amphetamines, opiates, and pcp.
If that's the case you need to be under the concentration of 50 ng/ml to get a negative. If the test indicates a positive they will use gas chromatography on the sample to verify, and the GC has a sensitivity of 15 ng/ml. So if you test positive on the first test legitimately you will test positive on the second verification. So the key is getting your concentration below 50 ng/ml.
marijuana metabolites get stored in fat and stay in the body for up to 30 days.
You need to get the concentration down below the cut off. Drinking lots of fluids now will do NOTHING. You need to dilute it when you actually pee. The liquid does not "flush" anything out of your system, it simply makes the concentration lower (you have the same amount of metabolite leaving your body, but a lot of extra urine makes the concentration lower). They will test for a few things after you piss:
Is it at least 2 ounces?
Is it within the acceptable temperature range? (not sure exactly, like 92-105*F or something - not an issue if using real urine)
Is it yellow colored? (take vitamins. diluted piss is clear, unless its loaded with excess vitamins
)
What is the creatine content? (If you dilute your urine it essentially becomes pure water. Eat red meat for several days before to elevate creatine levels so when you dilute it they are not suspiciously low)
In summation: Eat excess red meat and vitamins for 2-3 days before the test. Drink lots of water immediately preceding the test. Drink it the night before if it's a morning test. If it's later in the day you can wait and just drink it several hours before you go in.
Also do not use the first piss in the morning. The metabolites come out in the highest concentration in the first piss of the day because they built up all night. The same thing applies to the beginning of subsequent pisses. Try to piss for a couple seconds into the toilet first, then cut it off and get your actual sample mid stream. Then end of the sample is bad too, so use mid stream only.
