If it has any type of filter on the intake, that could be stopping up. It also has a flow adjustment on it. Make sure that there isn't anything clogging that area.

Hi pondmanimal, thanks for responding.

There is a little filter-type, screw-on thingy but is not obstructed by any debris. And on this particular pump there is no flow adjustment. Any other ideas? My turtle spitter awaits! lol

Did you pull out and clean the impeller? They get jammed up fairly easily with such things as plant fibers, string and hair. The small pumps are worse than larger pumps for this.

Yes, I did take it apart and clean it thoroughly. It's becoming very annoying. Just as I'm ready to toss the darn thing in the trash, I decide to give it yet another try. What could possibly be the problem if the motor is running, the parts are in correctly and no debris is causing the problem? I even tried to prime it by running the water hose into it in case there was an air block?? lol Just made sense to try when I can't think of what else it could be.

I would check it by running it in a tub of water completely disconnected from tubing. If it fails to move water, you know it is broken. Lowes is very good about taking stuff back.