I have 5 tanks, 2x240gal 2x 55 gal 1x 70 gal for filter media total about 700 gal. Heavily done in live rock and fake coral...All are interconnected by 4 inch tank to tank pass through portals totalling 24 feet long. For safety Timid or smaller fish can pick any tank they prefer although they do venture into the big boys tank, 1 xl queen, 1 LG asfur, several schooling mixed tangs and heniocus butterfly's. A happy pair of regal angels developed immediately and 3 others just swim around leisurely after a few days. Oh! Sumatra/ red sea/ Maldives regals are worth the extra bucks if you don't like netting dead Indonesian ones out in about 2 weeks. I have 4 additional sumatras from Pete's aquarium in fishkill NY arriving soon. All are born female. Longer bodied males morph later. Michael Hedges, Hawaiian knights saga