I started using polyquat this year in my inground pool and I have noticed my pool doesn't feel so 'slippery' on the walls and bottom anymore. We also had some tiny patches of mustard algae last year and I haven't had this problem at all this year. Even though I was pretty vigilant with the BBB method, sometimes my chlorine would drop more quickly than expected, almost as if the pool was on the verge of fighting something. This year I also added boric acid. For me, the combination seems to serve as a safety net for times when the chlorine isn't as high as it should be.