OK I'm going to be quite honest and to the point with this answer, because i know its what you need.
You are what we call in the service a "pot head". If you do not plan to stop smoking, please, please do everyone a favor including yourself and "do not take that test".
I understand that some people associate smoking drugs with having a good time as a teenager, but like you said "its time to grow up". I'm not saying don't ever take the test, but please wait. If you cannot give up smoking drugs outside of the military
What makes you believe or think that they will tolerate it, if you happen to slip through the cracks. If you get caught at the MEPS station, they will be watching you even more closely than before, especially your recruiter.
If you make it through, I'm going to familiarize you with a new acronym that you will most likely hear. UCMJ (Uniform Code of Military Justice) article# 83, 92 and 112a I'm sure they will tack on a few more also.
So take this info from a soldier that can still submit the necessary papers to start the process of an Article 15. Once you sign that contract, mom and dad cannot save you.
1. Dependency on illegal drugs is disqualifying.
2. Any history of drug use is potentially disqualifying.
3. Any history of dependency on alcohol is disqualifying