Hello. So I bought this product 2 days ago and first used it today. My pond is 4 feet wide and 2 feet deep. Not even 2 minutes after plugging in the cord and putting the pump in the pond, it stopped vibrating. It said it was submersible and can go in water max 4 feet with 80gph. Anyone know whats going on? If anyone has a pondmaster magnetic drive utility, can you tell me whether if I was doing something wrong? Was 2 feet too deep for this pump? Please help