Poll On Better Fish

out of all of those only

Kribs
convicts and
the electric yellows

could even fit one comfortably in that tank. though they could breed in it too.

I'm going to eliminate a few for breeding in a 20 gallon for you--these are obviously too large to be bred in a 20 gallon:

Green Terror
Jaguar
Gold SevERum
Red Devil

a few africans from Lake Malawi could live reasonably comfortably in that tank for a while. and lake tanganika shell dwellers could for life. A couple of convits could live in a 20 galloner happily for life i THINK..though one on its own may be better. Kribs i dont know much about but they do stay small but you may be able to make a community of them...if so you would want a few females and one male.

Let's talk about the size of the tank. I realize that you have called it a 20 gallon, but there are multiple 20 gallon dimensions, so we'd need to know some exact numbers in order to go further.

My bad, I didn't see the 20 gallon long in the top. That was what I needed to know.

You can somewhat reasonably stock a 20 long as if it were a 29 standard, but that needs to be modified a little bit...the pollution levels of the Cichlids would be the same, they'd just get the 29g surface area for aeration.

I would think that you could stock it like a 25 gallon for Cichlids, but I would have to have someone confirm it, as I'm now delving deep into the realm of theory.

Someone else will hopefully be able to run with that.

Matthew