Spa Pump Impellers
Impellers for spa and hot tub pumps are specific to the make, model and horsepower of a particular spa pump, and are not interchangeable. Be sure to select the correct replacement spa impeller, and to also replace the shaft seal at the same time. Spa pump impellers also often mate with an impeller wear ring, which slips over the front eye of the impeller, to prevent wear and seal up the gap between the impeller and the pump housing.
Spa pump impellers don't often wear out over time, and unless they are visibly broken, are often not the cause of pumping problems. Impellers can however become clogged with seeds or small debris, which can be cleaned by reaming the vanes with a small screwdriver or length of stiff wire.