Just curious...I always use the diluted method to check my FC level because I have a higher CYA Level and keep my FC pretty high-this saves me on drops. I use 1/2 pool water and 1/2 distilled water. I ran out of distilled so I used water that I was going to dump from my de-humidifyer for the test. No cholrine in it so I thought it would be fine. When I did the test the water turned light pink, not the usual dark pink. I did the test using all pool water and it was it's normal dark pink color. Why would the water from the de-humidifyer skew the result? Now I know not to use de-humidifyer water.