Interesting design , most use the pump to pump from pond into the filter. You want to pump from filter into the pond . Thats the way folks who use a settling chamber do it I belive .You might whant to look into adding one .With right size piping , pump and correct water levels it should work. Let us know how it goes.
Those of use who pump from pond to filter with gravity return need to insure that the return can handle more water than the pump is putting into the filter . In your case you need to insure that the feed to the filter can supply more water to the filter than the pump can pump out of the filter .