I added an pvc extension to the drain on the durso, about 8 inches with an end cap. Drilled 1/8th inch holes (probably a couple hundred). It didn't cause much drag, water level went up about 1/4 of an inch in the overflow.
I should have taken some! Sure don't. I'll take one tomorrow though, the tank's at my job, not home.
Where the drain is open.. the elbow facing down, I inserted the pvc into the elbow making the drain longer, going deeper into the overflow. I closed the open end off with the end cap. The water flows pretty freely through the holes but they need to be scrubbed occasionally to remove any debri buildup.