I smoked July, 15 and only once after not smoking for months because I assumed I was going back to school and not getting any interviews for work. While I received a call Saturday and have been drinking lots of water since. I should be getting tested Wednesday. Any way I can improve my chances?
In that short a time, less than 24 hours, I'm afraid there is nothing you can do. That's the bad news. The good news is it's been almost a month since you last smoked and you didn't smoke for months before the last time. You may very well have naturally reduced the level of THC in your fat cells to pass the test. All you can do is hope.
BTW... water doesn't help to eliminate the THC. It's stored in your fat cells and must be burned off with exercise. Some recommend Niacin to help, but seriously, intense exercise for several days is the only real way to burn the THC out of the fat cells.