Checks is correct. I have the skimmer/bubble trap box for my Remora and it works great, even with a bag of carbon in the bubble trap side of the box. No water overflows over the top, so the water is flowing through the carbon and out of the bottom opening.
I have my Remora with the Maxi-Jet 1200 on my 20-gallon reef. I have to clean the cup at least once per week. Even though the Remora is rated for upto about 70 gallons or so, for a 50-gallon, you might want to consider the Remora Pro. It is a little bigger and uses a bigger pump. I would feel more comfortable with the bigger skimmer.
Good Luck and Have Fun!!!;
