Please bear with me, we’re extremely new to this. I’m just trying to help out my husband while he’s away. We recently bought a property with about a 15 foot deep pond on the property. Everything has been running smoothly and all of a sudden it started running incredibly loud. We noticed that only one of two diffuser plates are working in the water. Honestly I have no idea where to start. I would assume something with the motor of course, but no idea.