Never Kept Cichla.....i would never have the tank for them. Have you googled Peacock Bass for adult pics?? Or read the threads here....i would guess 500 gallons would suffice for a small clan.....Bigger is better of course!
that should be fine for now but they will be around 12 inches long at a year old. Full grown can get to 3 1/2 feet. for that ull need somethin around 500 gallons.
there is a breed called cichla monoculus. it gets to be around 28 inches at full grown and thats the smallest. a 250 to 300 gallon tank would work for a school. but you would be fine with 1 to 4 in a 125 gallon
@ the OP, when dealing with all cichla you want Length and Width. Height is usually not to big an issue i would say anything above the standard 2ft should be fine unless your Cichla are gargantuan. But more importantly you want length and width. The Cichla should generally have about the length of itself + another half of itself for the width of the tank. Meaning as an adult you are dealing with a larger tank. Unfortunantly a 125 will not cut it. However, from juvi-semi adult it should last a while. Say 10months to a year? Really depends on what you are feeding it and how often + some other factors but i'm just touching the surface.