Parents Said I'm getting tested

So I just recently started smoking weed with a couple of my friends, one of them has a medical card so he went out and bought us about 4 grams... we smoked all of it in about 4 hours ( dumb I know)
a week goes by and I smoke two hits of Hash and then some weed mixed with a Hooka.. the next morning my parents tell me I'm getting tested in about 4 days for reasons unknown.

I am planning on going to the gym everyday for about 2 hours to run and lift weights as well as drink close to 2 plus Liters per day.

aside from working out and dilution is there any other advice anybody could give me or tips as to how to pass the test??