started and begins its operation of up and down movements to pump the slurry or liquid with suspended fines and particles to the surface the slurry progresses up the interior of the hollow rod string 125 along the liquid production path 155 at a velocity that will re entrain fines and particles that have settled out of the liquid from the previous pump cycle back into the liquid to be carried to the surface the fines that had settled out should have only settled on the top of the last check valve that the slurry passed before the pump shut down at the end of the previous pump cycle once the liquid level has been pump down conventional pump off control technology detects that the liquid level has diminished and preferably shuts down the pump and ends the pump cycle with a substantial volume of liquid delivered to the tubing annulus all of the liquid and solids in the liquid production path is preferably completely produced to the surface along with a substantial portion of newly added liquid however some operational schemes may not include a great amount of new liquid so the spacing of the check valves 145 may be more important ins some wells so that any fines that enter the interior of the hollow rod string 125 progress beyond at least one additional check valve at each pump cycle including the recognition that such fines will need to be re entrained at the start of each pump cycle and therefore on top of a check valve and must flow all the way beyond the next check valve to eventually make it fully to the surface.