PondMaster Pond Pumps - Pondmaster Impeller Replacement Be sure and clean any algae or debris from your old impeller before considering a replacement. Models 950 - 1800 are available in an ""A"" and ""B"" series. On the rear of your pump you will find a stamped letter. The ""B"" series is for current models. Your impeller may vary from the above picture. Smaller pumps have less fins. Sorry, NO RETURNS on impellers if the retail packaging has been opened. See all of our Pondmaster Pond Pumps Pondmaster Impeller Replacement PM 65