I have an above ground pool. It is 24' round and has 52" walls water level about 48". It holds around 18000 gallons of water if my calculations are correct.
I have a sand filter.
I have been using bleach and super shock.
I use baking soda and borax.
My readings are
FC 15 now it's much much higher
ph 7.5
TA 90
cya 50