I had a chance today to verify something I suspected about the white stuff. I've had problems with it twice since I installed. The first time, I was adding 10% to the tank that already had a few gallons of 6% in it, and this time I let the chlorine run out, so I was adding 6% to a tank of water.
Both times, I could clearly see the flow of the incoming chlorine disturbing the sediment on the bottom of the tank, even though I was pouring it more slowly than I normally do. The first time I was pouring more slowly because we had been discussing WS that day, and this time I poured very slowly in hopes of verifying my previous observation.
My theory/guess is that when adding the heavier liquid, it flows across the bottom of the tank and disturbs the sediment. If there are already a couple of gallons of liquid with the same density in there, what is being added is the same density as what's already there, so the flow is less concentrated on the bottom of the tank.
Like I said, I have zero WS other than these two times when I was adding a liquid that was more dense than the contents of the LQ tank.
Those of you that have WS problems: Do you often let the tank run out of bleach (or close)before adding? Those of you that don't have WS problems (Dave?) might want to try letting it run out to see if you have a similar experience when adding bleach to an LQ full of water.