Using an external overflow with 1" tube. Return pimp is a mag 9.5. 75g tank. Return pump is only at about 1/4 open on a valve I installed in the plumbing. So, I figured I am pumping about 235 gph. This is the max I can do without the pump overtaking bf overflowing my dt. Does this seem right? And is this flow rate going to work for a 75g?
Pictures show my overflow and the amount open in my ball valve. Horizontal is fully closed.
Pictures show my overflow and the amount open in my ball valve. Horizontal is fully closed.

