Quote Originally Posted by Burnt Toast
You would have to test his/her sample with a validity test strip to see that the creatinine and specific gravity are within satisfactory limits. These are essentially the same colorimetric tests that are used at the lab when they run the validity tests on the sample (which had become SOP in recent years, making sample "color" the least aspect in determining an overdiluted sample).
These kits are inexpensive and are found online by doing a Google search for "drug adulteration test kits"

Without the validity tests, you would have to chance it by taking his/her word that s/he had not consumed an abundant amount of fluids prior to donating the urine sample to you (iffy, iffy).

Do you have access to a sample from a different clean person?

I got it figured out. hes my bro and I live with him.... so I just told him he needs to stop drinking water as much.. I found out from a lab that you cant consume more than 40 oz of liquid in a 3 hour period. and i got him some vitamin waters, he takes creatine as a workout supplement and i will be using his first void of the day.. Test is Friday so I dont think I have enough time to get those drug adulteration test kits.