What is the correct way to view the results?
I'm trying to read my Nitrate levels but depending on how you place the tube on a white background the color changes. If i hold the tube directly on the white card so light cant penetrate the back of the tube, its darker than if i hold it a few inches away from the card where the light can penetrate all sides.
I'm trying to read my Nitrate levels but depending on how you place the tube on a white background the color changes. If i hold the tube directly on the white card so light cant penetrate the back of the tube, its darker than if i hold it a few inches away from the card where the light can penetrate all sides.