My 125 gallon tank has dual overflow chambers, and uses a Megaflow model 4 for wet/dry filtration. I also have a Fluval 304 for the polishing. I then have 4 korolia powerheads turned on/off randomly from a Red Sea Wavemaster Pro. The tank also contains 150 lbs of lace rock and 200 pounds of crushed coral.
Know as much about the creatures you plan on keeping before you ever actually have them.
African and Central American cichlids.
A sword of some type.