I can not find a protein skimmer that will fit in the Waterbox cube 20. I had a Hydor Koralia Nano-Skim Internal Protein Skimmer
which fit in the back and worked well, but restricted water flow causing the pump to run dry. I ordered another skimmer thinking that it would work, but the dimensions did not include the suction cups so it ended up not fitting. Does anyone know of a protein skimmer that will fit in the back chamber of the tank?