Quote Originally Posted by auntphibian View Post
Okay, I trudged to the pool in the pitch black and redid the CYA test, as you said. The reading is exactly the same. It does not read. Now what?
Do you mean that you diluted one part pool water with two parts tap water (as suggested by Pool Doc), and that the resulting mixture was still so cloudy that the black dot at the bottom of the tube disappeared very quickly -- i.e. with the water level lower than the '100' marking on the tube ? If that's the case, it would mean you have a LOT of CYA in your pool water.

Hopefully you had a decent amount of ambient light for reading the test -- going to the pool 'in the pitch black' doesn't sound promising for reading test results somehow