I added a gallon of CYA stabilizer for the first time ever at around 4pm and then tested at 10:30pm last night and got a reading of 30. Tested again this morning just to double check and got around 20. Does that make sense? Do I need to keep adding stabilizer to get closer to 30 again? Will the level of CYA drop that much over night? (Unless, of course I did the first test wrong, but I did double check it a few times and it looked like a clear 30).
If it matters, my FC has been all over the place. I am attempting to hold my CYA and FC levels steady enough to SLAM/shock my water so that I can clear up the cloudiness and finally get it suitable for swimming!