Green terror and Severum?

[Stanzzzz7]

My male hit a good nine inches within 2 years.
That was while constantly spawning which slows growth considerably. They are not a fast growing species but so many things can effect the growth of individual fish.

 

[Stanzzzz7]

To answer the original question. Personally speaking I would not put a Severum or a Gt in a 55. Severums get large and eat a lot.
Rivulatus get large and are intelligent energetic fish far to much so to spend a life confined to a 55.

 

[neutrino]

Sometimes I wonder at the different fish some people say grow slow that don't grow slow for me. Maybe it's partly perception compared to what you're used to, but for me green terrors don't grow slow, not the first year, and I've had a number of them over the years. Typical ime is 6 inches more or less in one year for males, then an inch or two per year for the next 2 or 3 years.