Thanks for the quick reply Pooldoc. I figured it had something to do with the swg but the reverse polarity self-cleaning feature flaking is a new twist I didn't think of. Thank you for the info .. I will get the k2006. I've always used my distributor supplied brand 4way and then I'll adjust the CA and TA (PH is running about 7.8 after muriatic acid seasonal adjustment; which has been a little high but okay). Next - I'm going to turn the salt gen off for a few weeks and go straight chlorine and vacuum the dust up to waste and see what happens. if it goes away, I'll turn the swg back on.