pool is 20ft by 10ft, sloping in the center with 3ft ends/5.5ft center. everything was fine until I ran out of trichlor tabs, chlorine level dropped to 0 and started using the trichlor plus tabs instead. here's the reading....
total hardness- very low
TC 0
FC 0
ph <6.8
alkalinity 180
stabilizer very low
some green algae on the walls despite 1 bottle 50% algaecide

is it possible to be acidic and have a high alkalinity? I checked it with 2 different brands of sticks and it's accurate
any ideas??
thanks