If you want a convict type I would go with one of its smaller cousins such as Honduran Red Points or Nanolutae. A single specimen will be fine. Both get to 4in give or take much better than possible final size of a standard Convict. A 40breeder those would be much better.
Don't overlook Apistogramma tho. Even with the small size very convict like in it's activity level. I had one that started in a 20Long. Eventually it made its way into a 125. Being low man in the pecking order was still very active.
Also they come in many different colors, red,orange,blue...
Also they come in many different colors, red,orange,blue...
Nanolutea are not piscivorous by any means, and not that it matters, but they can still reach 6" given a couple years. Studies on stomach contents found most of their diet is plant matter. Mine graze slime algae and eat floating plants. HRPs are also not actively piscivorous, but are very good wet pets. Amatitlania/cryptoheros in general are not very competent when put up to the task of eating things. My big male Rio bagaces doesn't know how to eat crickets.
Dwarf pikes would physically fit in a 20 long, but that's not to say they'd fare well. I personally think they'd do fine, I had a small compressiceps in a 30 long, but they are VERY active. I do recommend them however, very fun fish. Pike livebearers, acaras from cichlasoma, blue gularis killis, some of the larger betta species, all good options if you want something to feed tiny fish and bugs. That can fit in a 20 long for awhile.
Admittedly I do occasionally feed my male nanolutea bugs, but then again he is a relatively huge 4 inch male, which would take years of growth from the size they're normally sold at to achieve.
Dwarf pikes would physically fit in a 20 long, but that's not to say they'd fare well. I personally think they'd do fine, I had a small compressiceps in a 30 long, but they are VERY active. I do recommend them however, very fun fish. Pike livebearers, acaras from cichlasoma, blue gularis killis, some of the larger betta species, all good options if you want something to feed tiny fish and bugs. That can fit in a 20 long for awhile.
Admittedly I do occasionally feed my male nanolutea bugs, but then again he is a relatively huge 4 inch male, which would take years of growth from the size they're normally sold at to achieve.
