Well I just took it. Drank probably about 4-5 glasses of water/coffee over the four hour period preceding the test, so most likely somewhere in the range of 32-40oz. I Don't think that is too much. My urine is usually clear even if I don't drink a lot, but it was fairly clear with a light yellow color, consistent with my normal voids throughout the day. I will update when I know the results, wish me luck!