its difficult to see in the picture, but I think you ether have to many bio balls or you have a sump thats too small. what is the size of the tank you are filtering? as far as I understand, and I am willing to be corrected, you need 1 gallon of bio balls to filter 30 gallons of water. Your sump should be 1/3 the size of your tank, this is to allow for sufficiant water capacity for your tank. Anyone else have an opionion on this?