I have added CYA twice now. A few weeks ago I added 40 ounces and a week later it tested around 20, probably under that. I added another 32 ounces about a week and a half ago and I can still see the black dot, granted it's really really light gray. We have had quite a few rain showers during all this time. Could this affect it? All my other levels look pretty good.
CC- changes daily I have to add bleach every day
FC- .5 or lower
CYA- low low low
Could I have something growing in my pool eating my CYA? I'm at a loss. When it's not raining it's been very sunny and humid. My pool is in direct sunlight all day and the water temp is usually 86-88 degrees.