Thanks for reply . CYA is 90 . Both of the last two years I had periods of very clear water and everything in balance but could not get a chlorine reading . I did partial drain both years and then did a high shock after . Nobody could explain after 20 plus years why this problem was occurring . After last year which occurred around July I switched to bleach only and have not had a issue holding chlorine since . With a CYA of 90 I try to hold between 5-10 which was the recommendation last year . My concern other than normal check of chlorine and adjustment with addition of bleach I do nothing else .
Pool usage is low as its a few adults daily unless the grandchildren come home which might be once a month .
I do have a concern as the black birds have determine my pool is the deposit zone for their afterbirth . I have installed the fish line x cross plus the owl and some big eyes with improved results but appears now they have found ways to get through this defense system . Once birthing stops this will stop.
So when you super chlorinate what does this mean ? Do you only use bleach and how often?