What's your TA? High TA and SWCG use tend to cause high pH.

Bleach is basic but it's reactions are acidic, use of Sodium Hypochlorite is nearly pH neutral.

WaterBear has had success limiting SWCG pH rise by keeping 70 TA, maximum SWCG mfg. reccommended CYA level and adding 50ppm Borates to the water.