This is mostly to thank those of you who helped me with this problem.
To recap for newbies, I came back from a vacation to find that I had lots of white flakes floating around the hot tub. It almost looked like dandruff! The stuff would disappear if you rubbed it between your fingers.
I was told that it was "paper mold", an organic biofilm that was growing in the plumbing of the spa.
I tried sanitizing it, but nothing worked.
Here is what I finally did;
I put in LOTS of dichlor. I think it was about 8 oz. I washed and chemically cleaned the filters (Tri-X) twice and then physically washed them every day for a week. I ran the pumps with the diverter in the 12 oclock position for several hours and drained about a gallon out through the two ground level drains to make sure the high chlorine liquid purged that area.
It took about a week for the chlorine levels to drop down to normal levels, despite taking Chas' advice of throwing my kids in a few times! Once the CL levels dropped, the rest of the chemistry seemed to also drop back into normal. I have seen no white flakes in a week.
Thanks to everyone for the great advice! Especially to Chas who put up with a phone call too!
