Quote Originally Posted by waterbear View Post
If you have algae in the water then your water will be cloudy, not clear. Since the CYA test is a turbidity test the extra cloudiness from the algae will give a false high reading on the CYA so if you CYA is testing the same it very possibly is lower than it was. Wait for the pool to clear and then retest your CYA.
I'd kind of filed that as a possibility to give me an artificially high CYA reading, which I had expected to be in the 20ppm range. Still in shock over the alkalinity drop. Fortunately I have a ready source of alkalinity increaser in my fill water. Maybe for one season I'll be able to vacuum and backwash like a normal person.