Well, a warm day Saturday so I went ahead and completed my first water change. Initial fill was mid August. I knew it was time because even though all readings were OK, I just learned about TDS and that this is what makes (or one thing that can do so) the water cloudy when the jets are on. And cloudy it was. No odor, bromine, PH, TA all OK. So, a hose to the drain and a sub pump and two hours later it was bone dry time. Cleaned and polished the tub, 8 oz Metal-X + 1 pack spa shock + 1 ounce Spa Blue and viola....7 hours later back to 102 with crystal clear water. Very easy task made easier by a few Bass Ales.