Here's images of my pump (the Pentair Sta-Rite P6RA6F-206L Max-E-Pro). I took off the motor part and AFAIK the impeller was clean (I can't physically move anything on either side of this assembly).

I'm hoping the pump has just gone bad, as I ordered another one (the same kind) which should be relatively easy to replace (obviously I could easily just put the pump part back in, but I most likely will swap out the whole pre-filter and housing, as it appears to be a simple screw set up that, at the most, will only require me to make some fittings at the pump side, which is pre-threaded on both connectors).