My pool numbers are;
My fill water has a CH of 200 and a TA of 220. As I add water , I also have to add acid to reduce the TA or I get a run away PH increase. Currently I just reduced my TA from 110 to 80 so my PH has not fully recovered at this point. It will eventually get up to 7.8 where it will stay until I add more fill water.
The problem is that at the beginning of the season my CYA was at 60, I have only back washed my filter 1 time this season and after that back wash was when I measured the CYA. I have also added 4 - 5 pounds of CYA this season as I'm trying to hit the recommended 70 for my SWG.
I have added CYA via a hose stocking in front of a return jet. I've added it immediately following my back washing directly to the skimmer. Last week I had 2 pounds of it dissolve in the stocking in 4 hours! I did not squeezing, squishing or anything, just hung it in front of the return jet.
By my calculations I've added enough CYA to get my CYA to ~90, but I'm still stuck at 50.
So a couple questions, I bought my CYA last year so it is ~1 year old, does it go bad in a year? Though it is all gone now and I just bought some more. Can my TA reduction (which happens every couple of weeks depending on rain fall and the need for fill water) be reducing my CYA also? I know that the common thinking is that you cannot get rid of CYA except with a partial refill, but I can't seem to get my CYA up and keep it up.
I don't have an automatic refill on my pool, and I'm only putting about 1.5 inches of water per week in my pool, so I don't think it is leaking out anywhere.
I'm about ready to start using dichlor as it is acidic and adds CYA to augment my SWG instead of bleach. I seem to be added both acid and CYA separately anyway.