So, did a full test on Friday to open the pool side for swimming - we use the spa all winter long. Water was clear, but I noticed that the CL level seemed low considering I had set the cell at 100% on a 5 hour a day run. I soon discovered why: for the 2nd year in a row, CYA was zero. Added 4lbs to get it up to 40. Had to do the same last spring. What would cause CYA only to disappear over the course of a year?
My salt level is actually creeping up
My borate level is stable
My calcium is also creeping up (around 750 now - I'm in AZ, so 750 is normal here)
Other stats:
11k pool/spa combo, SWG, pebble sheen finish, cartridge filter
Everything I've read here says the only way to lower CYA is thru loss of water. I have no leaks, minimal splash out, and don't backwash. In addition the salt and borates are mostly stable (salt is around 3800 and it started at 3200 almost 3 years ago).
What could chemically be causing loss of CYA?
My salt level is actually creeping up
My borate level is stable
My calcium is also creeping up (around 750 now - I'm in AZ, so 750 is normal here)
Other stats:
11k pool/spa combo, SWG, pebble sheen finish, cartridge filter
Everything I've read here says the only way to lower CYA is thru loss of water. I have no leaks, minimal splash out, and don't backwash. In addition the salt and borates are mostly stable (salt is around 3800 and it started at 3200 almost 3 years ago).
What could chemically be causing loss of CYA?