Pulled the spray arms and filters out for a cleaning, noticed some debris in the pump inlet under the filter. It turned out to be three small pebbles, slightly too big to fit between the inlet strakes. I pulled the top off the impeller housing, impeller looks fine, but the inside of the housing is thoroughly knicked up. Looking at the filter, it seems designed to allow larger objects to fall down the center. I have some stainless screen, might need to mod that filter. Soaked it in vinegar to get the calcium off, should get some better flow now.