I am currently using the Bulk Reef Supply dual reactor with the recommended amount of ROX carbon and GFO. The pump I am using is a MJ 1200. I noticed the other day that with the ball valve wide open I wasnt getting much flow through the GFO stage. I took the pump and reactor apart, changed all the media, cleaned it out and cleaned the pump out. Then it worked fine. After about two days once again the flow is restricted. Does this mean the pump is not powerful enough? Is there a trick to getting it to work just right?