I PASSED!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! lol I passed.
I took 4 extra strength Excedrin 250 mg (with caffine and acetaminophen) 3 hours before. I drank 2 gallons of water and 64 oz Gatorade. I also took half a bottle of b12 but my piss was still clear and to top it off 1500 mg niacin no-flush (3 pills). I went in pissed clear. The person who administered the test said I might have to take it again and asked why my piss was so clear. I just told here straight up I went to taco bell right before and had 2 huge 32 oz sodas and that mountain dew is a laxative. I really do doubt the niacin does anything.
As long as you piss clear and can keep your creatine levels up you should be fine. Most labs do check for dilution but with clear piss it should put you down under a threshold of 50mg thc.