120g 4x2x2 minimum, a 180 6x2x2 would be perfect to keep a fahaka happy for life. fahaka's are messy pigs, so be prepared to do atleast 50% water changes weekly/biweekly.
no tankmates, grows to 18", needs a steady diet of meaty and hard/shelled foods to keep their teeth worn down, temp 80f, extremely messy fish that are also very sensitive to water quality,heavy filtration is a must, fully freshwater.