are you dumping water back into the cheato section? If so, why not dump it back into the skimmer section? this way, it gets skimmed again, and still goes through the cheato section.
Also, would it not be better to place the bubble trap directly in front of the return section, instead of immediately following the skimmer? Any micro bubbles created in the cheato section, does not have a bubble trap before being pumped to the DT.