When you add water to dilute urine in a drug test what will that do?

It won't effect the test findings but they can tell as you found out if you try to falsify the test.
They will be able to tell what drugs you took and they really don't care when you took them just the fact that they are there is the point.

If you are at a methadone clinic and have carries then obviously you could and should lose them. If you don't have carries then they can and sahould lower your dose or they can start you on a administrative detox which I don't agree with if this is your first offense

If this is testing for probation ect then I have no idea about that as I'm at a clinic and don't have experience with the other.

Just so you know, there is nothing you can do to change the test results of a urine tox. Even drinking tons of fluid will show up as a high creatine level and they will assume that the person was trying to wash something out of their system which just doesn't work. If you put something in your body it is going to show up no matter what..

So I hope you don't get into to much trouble and I also hope that you continue in your recovery, good luck...