I just recently replaced the main aerators(which serve to reciculate the water and pump out). Well I am still having issues with recirculation. They will work fine at first and will recirculate but randomly throughout the day will slow way down and have almost zero water being pumped through, but the aerator pumps still are running. I'm very confused and am tired of having to babysit fish all day long. Anyone have an answer? Thanks in advance!