I did this test a week ago when I first received the TF-100 and it was 190. The test worked just like the instructions said, went from green to red. I have tried this twice since and it starts green and then goes clear. I have added 25 drops and it stays clear. Any idea what I am doing wrong? I fill to 25ml, add 2 drops 0007, mix, add 5 drops 0008, mix then start adding 0009 one drop at a time wiping and swirling between drops.