I saw the post it is best to test cya outdoor with your back to the sun, is there a trick for inside? I've added 5 pound stabilizer. The pool store said it was a 5 after adding. When I pour in, it fades at 50 but I can kinda see it. I don't have the sun option right now. Didn't know if I was being too exact about it disappearing. Thanks, Brenda