My reef on the main floor (roughly 300 gallons) empties into the basement to its own room where there is about 200 more gallons in frag tanks, algae scrubber and sumps. A big Iwaki pump then lifts the processed water back upstairs to the main reef. Same setup has run about 21 years now.
Picture of the outside corner reef is on the main floor, subsequent pictures are from the basement fish room. I use rubber maid tubs and Brute trash cans as sumps and frag tanks. I also have a 6' long glass frag tank with a moving led
light in the basement on the same system.