Options for 55 gallon

[Gourami Swami]

Agree with duanes on the butti; even a 180, which seems quite large, may be too small for a pair of them. Butti's are one of the few cichlids which get too large for most home aquaria, along with dovii and umbee.

Aside from the species I listed, most CA cichlids would work just fine as a pair in the 180, and you could grow them out in a 55. Few I would consider if this were my tank; amphilophus species (like midas), Red tiger motaguense, vieja/paratheraps species

These fish I listed are from CA and like harder, higher pH water. If your water source has a low pH and is more soft, I would recommend south American fish like perhaps some crenicichla atabapo, Ornatum, or atromaculatum

 

[duanes]

I agree with Gourami Swami about tailoring the fish you buy, to your specific tap water type. Although there are many fish tolerant of opposite than their natural normally evolved water conditions, in many cases out of the environmental norm water can produce long term health problems in many over time.
You can find out your specific tap water parameters from your local water suppliers web site, and/ or EPA water quality report.
This can go a long way to insuring success in fish keeping. All water is not the same, and at times can be drastically different.
Type in your city name, followed by the words "water quality report".
And just an aside Central and South America are not the same, as are the geographic differences in fish.
The water in Central America is generally hard, ph 8-9.
South America is so large it has many different water types.
The Amazon area is usually quite soft with a pH below 7, often in the 4-6 range.
The area west of the Andes is more neutral around 7 and more alkaline.
The countries of Uruguay , Argentina, even Southern Brazil are much cooler than the northern Amazon countries, and to stay healthy the fish from the south require cooler conditions, and even a winter cool down of sorts,
Random combinations of cichlids from different areas, can sometimes be problems in the making.

 

[Jrenwa]

Thanks guys, I think Iam going to go with a Green Terror species. I bought 4 juveniles hope fully I will end up with a pair. Bought 2 pictus cats also, should be fun!