Never have algae problem. This year CC always at 1.0. No overnight chlorine loss. Pool is crystal clear( use borates). Reagent for CC is almost out. Is it possible the reagent is just old? I leave it inside and it’s only about a year old. When I put drops in it just gradually turns my water pink. Have a robot, been slamming, no change. If I was losing chlorine at night I would understand. The only place I haven’t messed with us behind the light. Water is very cold and never had a problem there. Could it be the reagent is out of whack since it’s almost empty?