A 55G is only 12" wide which makes the bubble trap even more of an issue. The flow will be going so fast through the trap that bubbles will be carried right through. It will act as a bubble transport channel and actually make it worse.
The theory of a bubble trap is as the water is traveling downward, the bubbles rise up AGAINST that flow to the surface. Tiny micro bubbles in SW have very little buoyancy. For them to rise against a downward flow, that flow must be very slow. Much slower than whet it would be in a 12" wide sump with a 1200 GPH pump or smaller for that matter.
The idea is, dont send the bubbles down into the return chamber where the pump can pick them up and send them to the display. It is simple to do that. Keep the bubbles on the surface.
If you aren't too far along, I would also recommend using a 75G instead. The wider 18" sump is much nicer to work with not just for this, but also for fitting a larger skimmer.
If you feel you must use a trap, make it very wide on the left side since that is where the bubbles are originating from.