cygnusecks - I believe they meant that they can use the same sample to take another look at the results in case of doubt. You have to do it all over again for the other tests, but this test you can just add the same sample back into the tube to see if your eyes see the same thing.

My question always has been - how high is waist high? I'd rather Ben put a number like 2 feet, 18 inches, etc. on the instructions. I'm over 6', but someone else may be 4'6" and have shorter to their waist.

Glad to read that it is as subjective as I thought.