Was doing research on detection times for blood test since I got screwed on an OWI deal. Found this: http://www.nhtsa.dot.gov/people/injury/research/job185drugs/drugs_web.pdf This is the national highway traffic safety administration Im thinking this is what all the DRE's read when they are getting trained. First of all: Every state is different!!! Go to LegalJoint: Washington Lawyers: Stiley and Cikutovich, Criminal Defense, Medical Marijuana Law On the left of the page you can look up the laws for each state. Unfortunately for me I was caught in one of the crappiest states in the USA! In Indiana, took a blood test and 24 hours after I smoked, could of had THC level <5ng/mL Still dont know the results yet...but of course in Indiana they have a zero tolerance drugged driving law. This means that if even 1ng/mL is found, I am still F'ed in the A! Again....from what I read in this booklet, after 12 hours of abstaining, the levels should be as low a 1ng/mL.....and if you so happen to be in about 45 or so of the other states in America, you will be fine. Hopes this helps anyone who might be in the same type of situation. And like I said, all states are different. Go to LegalJoint: Washington Lawyers: Stiley and Cikutovich, Criminal Defense, Medical Marijuana Law and find out. I actually found out that in the state that I live in (Ohio) you can grow plants as long as the buds dont amount to over 100 grams and its only a payout ticket. I think Indiana is one of the strictest though.