Someone walked into Fastest Labs of Webster this week and asked me if adding water to a urine drug test will make a positive test negative. I would say the chances are very (VERY) slim.
First, we measure the temperature of your urine. Add too much water, and it will be too cold. Normal is 90 to 100 degrees F. There is no source of clear water in the rest room where you provide the sample. The water in the toilet is blue for a reason. If you use that it will make the sample look funny.
When we send a sample to our outside lab they measure two things in the urine to detect dilution. That is specific gravity (SG) and creatinine. The reference value for SG is 1.000 which is the level of distilled water. Normal SG in urine varies from 1.005 to 1.030. If the sample is too close to distilled water the sample will become suspect. Creatinine, a muscle waste product, should be above 20 mg/dl. Again, if this is off the sample will throw a red flag at the lab. So not only do you need to find a way to sneak in clean water, you need to know how much to put in without creating suspicion. Then it needs to be enough to throw off the test. That’s a lot of variables to beat.
Your best answer to beating a drug test is to beat the habit. Many employers are sending employees or candidates for employment in for several tests. It is getting more common to see urine and hair testing in tandem. Urine gives the employer peace of mind knowing that the candidate is not currently using drugs. The hair test furthers that by providing history of drug use. So beat the habit, it’s not worth it to lose your job over drugs.