Thinking about it I see why it would not work. 1100 gph is a lot to get
through stand pipes. I assume the tank is drilled with 3/4" ID
bulkheads. Reducing the flow would help some but it is hard on the pump
and if I recall the Mag doesn't handle high head pressure very well. It
may be the best you can do it minimize the turbulence and air contant
(no right angles, foam instead of bio-balls, stand pipe with 3/8" holes
drilled up the side, etc.).

This is the problem with sump systems. They were designed with marine
systems in mind where maximizing the O2 is desired and they did not
have to figure out how to move the water around without removing the
CO2.