So my wife and I are thinking of dividing the 29 gallon tank that is just kind of setting around right now for our three pairs of clowns. I am wanting to divide these using black acrylic, but I'm having a hard time finding some. This would set up behind a false wall behind my 40 gallon that has a 14 gallon tank underneath it. I would probably put a bigger tank underneath for the sump. The sump will be for the 29 gallon and my 40 gallon breeder DT that has softies in it for coral. What would be a good size sump for 69 gallons of water volume in order to keep the water quality up? My current stand is approx 36" long x 17" wide x 27" tall inside. I might be able to convince my wife to let me build a new stand for the 29 gallon since it is just sitting on a metal stand that came with the tank.