We started with all new water June 1 this year, and started BBB a week later. It's been clear blue so far but I noticed that it won't hold 1.5 ppm chlorine (OTO) overnight anymore, so I just put a big jug (174 ounces) of the 6% bleach in - 15,000 IG pool, CYA ~30ppm. Never really had a water quality problem, but the water now is -really- clear.