Thank you all for your responses. I apologize for the delay in answering. I thought I had email notification set up and apparently did not.

I expect the kit to be here by Tuesday or Wednesday. I've brushed a few times and it is only coming back only in few spots and in smaller areas. I've also used 3 gallons of 8% 2x times since posting. I'll report tests as soon as possible.

Any hints or tips on using the the test kit for the first time user?