I have a mesh cover and opened to a swamp. Still had around 30ppm CYA when I closed with around 70ppm. I only pumped the pool water once this year around the beginning of March because it was getting high. When I opened it beginning of April, I didn't have to fill it at all.
If you ever want to check ammonia on the spot, go to a fish store and buy an API fish tank test kit that test for ammonia. I've only dealt with ammonia when I went without a cover and had a lot of leafy debris in the pool.
If you ever want to check ammonia on the spot, go to a fish store and buy an API fish tank test kit that test for ammonia. I've only dealt with ammonia when I went without a cover and had a lot of leafy debris in the pool.