Hello everyone. I recently moved to a new house with a pool and I have been reading up this forum and started using BBB method.

The pool, in-ground 25k gallon, water is pretty clear now, but I still get algae on the wall even though I keep chlorine level at above 5ppm all the time.

I recently got the testing kid everyone is recommending and found that CYA is somewhere between 240-300. I had to dilute the water twice. and ph level is 7.5.

Is having CYA@240 the cause of my algae problem? How much water should I replace in order to bring it down to the acceptable level? say 50?