Bubbles in Biocube
 

I've had my 14 gallon biocube running for a few months and recently it started spewing out all kinds of bubbles. Anyone had this problem and fixed it? I've checked that the water level wasn't low, removed the bioballs, cleaned the pump, checked for air leaks....what am I missing?

Have you checked your return line from your pump? it may have a split or small hole and it's acting like a ventri pulling in air.