i jus bought a brand new fx5 today and i put all the media in.set it up on my 150 gal with nothing but water in the tank.when i plug the filter in all u hear is the motor but its not sucking water in.i left it plug for about 30 mins and it stops then it starts again making the same noise.i unplugged it and plugged it back,same thing.what should i do?is this common for fx5's or is mine a defect?thanks in advance.