A Green Terror is a type of cichlid fish, which can grow up to six inches in length. They are a hardy species and make an excellent choice for beginner aquarists. When it comes to tank size, the bigger the better; however, they do need at least 50 gallons of water when fully grown. It's important to consider that these fish love to dig and rearrange rocks in their tanks, so you'll want one with plenty of floor space as well. Additionally, you should provide them with plenty of hiding spaces such as driftwood or rock caves where they can retreat if they feel threatened or stressed out by other tankmates. A Green Terror needs lots of good quality filtration and regular partial water changes should be done weekly or bi-weekly depending on your bioload (amount of fish). All in all, aquariums for Green Terrors should be at least 50 gallons in capacity but larger tanks offer more swimming space for these active fishes and allow owners to keep multiple specimens together without running into overcrowding issues.