Use the BBB method and pool owner since 1986. First time ever on opening my CYA level was 25 and had difficulty getting a chlorine level . Readings today were FC 1.5 ,Hardness 210,Alk 100 ,PH 7.4 and CYA 30-35 . Water is perfectly clear . I try to hold 3-4 chlorine . Is my CYA level too low ? Why cant maintain chlorine .