personally I'd rather see cons or fm's in a breeder setup in a 20 gallon and not a 20 long though a 29 would be much better than either. true, in most cases cichlids don't need a whole lot of height, but also imo 17" should be the minimum height for any cichlid with potential to grow 4" or more, especially in a breeder setup. I had a pair of cons in a 20 L and the male was no more than 2.5" and the female 2" but once the fry were free swimming the female relentlessly harrassed the male and almost killed him.
what generally happens when a pair breeds is that the female stays in the nest area and guards the fry close up while the male patrols the surrounding area usually hovering several inches above the nest watching for potential threats. in a 20L which is only 12" tall the male doesn't have much room to hover above the nest when you take into account there usually is some kind of cave that they breed in, as well as gravel bed taking up several inches in height. this is just my opinion and you're free to try and see how it works for you. not all pairs have the same personality. My opinion is still that a 20L is not big enough for either species for life, especially if you want them to grow to full size.
what generally happens when a pair breeds is that the female stays in the nest area and guards the fry close up while the male patrols the surrounding area usually hovering several inches above the nest watching for potential threats. in a 20L which is only 12" tall the male doesn't have much room to hover above the nest when you take into account there usually is some kind of cave that they breed in, as well as gravel bed taking up several inches in height. this is just my opinion and you're free to try and see how it works for you. not all pairs have the same personality. My opinion is still that a 20L is not big enough for either species for life, especially if you want them to grow to full size.
