SWSCJ
Aquarium Advice Freak
Pulled out one of the 75s, drilled it (2 -1" drains and a 3/4" return), and painted the back black. Had an extra chamber in the 450s sump, actually use to be the original refugium. I added a new 30 gal refugium when I bought the tank and joined them with bulkheads. I had an extra 3/4" feed off the manifold which is fed by the main return pump. I should be able to get 600-700gph. Going to drain into the unused 10 gal sump chamber with filter sock and small skimmer (rated for 150 gal).