Rainbow Cichlids Questions?

[joyboy]

I'm getting some new fish and i was suggested on here to get some Rainbow Cichlids for my community tank. I just wanted some personal experiences on whether they can be aggressive to other fish or not. I can get 2 rainbow cichlids or 4 sterbai corys. My tank is 4 foot (about 50 gallon) and currently has 10 cardinals, 10 rummynose, 5 striped kuhli Loaches, 2 dwarf gouramis).

 

[thereverendturtle]

In my experience they are relatively peaceful, but at full size your cardinals may start to disappear.

 

[OldMan47]

Mine were fairly peaceful members of their big community tank but they were very territorial when they decided to breed. This is what they looked like. They did like to hang together. That picture is in a 120 gallon 6 foot long tank and only one of them wasn't in the picture.

This is an attentive parent in full breeding colors. The black lower section is a warning to other fish to stay away and it had better be heeded.