did you mean 180 gallons or 108 gallons? cause 108 is kind of an odd number for a tank, but whatever, I have a 125 and just traded my three Falcatus in because the tank was too small. There super fast and have a tendency to break there snouts on the glass trying to swim away, very skittish. Mine were about 4 inches and I felt the 125 was way to small, they need a pretty wide tank as well as long due to how fast they can swim. Im planning a 240gallon and then I will get some more, but its pretty risky to put them in anything shorter than 6feet by 2 feet, I just saw a 10incher at a LFS with its snout permanantlly crushed inward, looked very painful and looked like it was gonna have a hard time feeding. that all being said... they like neutral to slightly acidic water, basic amazon type water pretty much, you can have plants with them, there teeth are useless for anything but spearing fish, which is the only thing they will eat, no dead fish at all, all live fish, that can get very expensive too. there skittish but as a loose schooling fish will like it a lot better if there are at least 3 in there. they can eat fish two thirds there own body length so any fish bigger than that will be totally fine with them unless they harrass the cudas, they really have no defense exept there incredible speed. there great fish, but need a huge aquarium to really behold there interesting behavior and keep them healthy, pardon my grammar too, I just start typing and dont pay attention, hope this helps you decide
