New sweep has stopped moving / Dust comes out
My Polaris positive pressure (360?) is less than 2 months old. It has very noticably slowed speed over time despite regularly cleaning the bag, the catch at the beginning of the hose and the collection filter near the equipment. But in the last several days it has basically stopped all movement -- it may move an inch every hour or so but that could just be drifting in the current. This morning I turned off the filter to check and thoroughly clean the debris catch at the beginning of the hose and when I turned the filter back on I watched the sweep closely. For about 10-20 seconds it came back to life at full speed then it came to a halt again and for a moment some kind of fine dust seemed to come through the bag.
Any ideas what could be going on? Could it be DE? I recently did a backwash, though everything seemed to go fine with it. It properly reduced the pressure in the filter as expected, no DE appeared to leak out at the time and if anything I was extra conservative in how long I backwashed and made sure I had clear water and how little new DE I put in and in putting it in slowly. I just don't know what else the dust would be or why the new sweep would be grinding to a halt.