Re: What causes the impeller to go bad?
All the advice I've had says replace the impeller once every 5 years, with light duty/weekend use (like on fresh water lakes, weekends, etc). I'm sure that salt water or heavy sediment use would need more frequent changes.<br /><br />The Selec book as an impressive set of photos on what an impeller looks like after just a few minutes (seconds, really) of use w/o water. If you clog your intakes or otherwise restrict the water flow, the impeller will be shot quite quickly. Soon after, your powerhead will be shot too!<br /><br />Better safe than sorry!<br />B