Hey fastaeda, haven't had an experience with these fish, but what is your temperature at? I ask this cus I found this online, not sure about how accurate it is though.
Temperature: Prefers water a little cooler than most other South American cichlids. Somewhere in the range 70-77°F (21-25°C) is best. Most experts agree that the species does best with an 'overwintering' period of 3-4 months, during which the temperature is maintained around 60-64°F (16-18°C). This simulates the changing seasons in its natural, subtropical waters. It's thought that the lifespan of the fish may be reduced substantially without this artificial 'winter'. It may be worth investing in a programmable chiller for a tank containing this species in order to maintain these very specific conditions. Unfortunatel,y this adds significant cost to the setup, making it an expensive proposition. - www.seriouslyfish.com