Just my preference...but I would ditch the hose and barb, especially the check valve on the ball. I look very similar to the one they sell at HD. It's not reef safe . The spring inside will rust and and cause major issue. Back to the plumbing, I would use a "wye" to split the return with the ball as is. Not sure what pump you got right there and the height of the top, you be loosing major head lose. I would ditch the bottom return, (maybe use it as a WC drain).