I have a huge skimmer chamber after the fuge and a bubble trap and everything gets through. Take a magnifying glass and closely examine your DT glass and the return chamber of your pump and the overflow if your tank has them. If you can see some microfauna on all of these, I would guess that you have enough getting to the DT to sustain your goby. Remember, its not just copepods that they eat. There are other little critters they feast on.See I just don't think the microfauna can evade my skimmer and bubble trap to get to the return chamber in sufficient numbers. Another poster explained to me how he rinses his chaeto in old tank water to release all the pods then adds that to the tank.

