I am a former shop teacher turned youth minister renting a house with a pool and trying not to go broke.
Found this site while trying to trouble shoot the pool.
Using HUGE amounts of Chlorine for 27K gal.
Got some numbers from the local pool store that show the CYA to be about 120
Going to drain about half of the water and replace it.
Giving up the "pool chemicals" for the BBB.
I have a 27K gal roughly oval shaped in ground plaster pool.
Auto Chlorination that can't keep up
2.5 HP filter pump
1.25 HP pool sweep pump
1 B E A Utiful wife.
Living in the country west of Houston