Fill up a bucket of water, hook up the Magnum, prime it, and plug it in. If it runs, it works. If it doesn't run, or if it sounds funky, go to Marineland.com and get their 1-800 customer service phone number, and give them a call. Great company, very satisfied with their customer service.
~~Colesea
. but my question is how do i know if my Magnum is working ???.