Well I have decided to not use the strip since I have read people failing the test while using it. I guess I will be using the clean ureasample with my own urine diluted for a backup. Since the at home test came back negative yesterday dilution would probably be a good backup. My only question is on the at home test if the line is visible, but not as dark as the control does this mean that you are close to the cutoff? The only error in these test is when you are close to the cutoff. Answers, recommendations or suggestions would be greatly appreciated. Thanks.....