I just woke up from a nap and was just laying there recovering and as I was doing so I heard a lot of thumping and it was kinda rythmic. I was looking around but could not see anything and then I thought "THE FILTER!!!" 
So I got up to investigate and it turns out my fish had just been banging around and knocked the end and air line off of my bubble wall. 
So I got up to investigate and it turns out my fish had just been banging around and knocked the end and air line off of my bubble wall. 