I have to bring a photo-copy an at-home drug test which I am administering myself. I know if I use my urine it will come up positive. If I test with water instead will it show up as a negative result? Or will it come up as an invalid result? It is one of those cheap tests you can buy at any CVS. Please, no nasty comments saying not to use drugs. I only want the answer to my question. Yes I know that not using drugs in the first place will show a negative result, but it's a bit too late for that now. Will water work to make it appear as a negative? I would come up positive for opiates. Is there any way to get them out of my system quickly?