Recently my Iwaki or is it Ikawi? pump has been giving alot of micro bubble in the return.  The strange thing is that I have the return split into 3 and only 1 return head is putting microbubles in the tank.  Is there anything I should do about it.  Do the microbubles harm anything.  Its hard to describe and hard to getting the bubbles in the picture.  :?:   Any thoughts?