Slacker,
All sorts of good things you could do with it,now that it's more a sump than a "filter." You could add even more liverock, esp. if you're trying to dampen the noise! Or, depending on the size and arrangement of the former wet/dry, you might consider an additional sandbed. Additionally, you could also place macroalgae in it under lights for additional nutrient removal as you harvest the algae. Just some thoughts.
regards,
-rw