Ok hold up, you say you have a 10g??? with a peacock cichlid and a pleco???? Ok this is extremely to small of a tank for those fish, for any cichlid! Peacocks need at least a 55 gallon tank or larger for these fish. No cichlid will be able to thrive, or even survive in a tank that small. You need to get a larger tank, possibly 40 - 55 gallon at the least. And if you intend on over stocking for aggression, get at least 600 gph of filtration, 300w heater, ect. In this hobby, don't just go out and buy a tank and some fish and not do your research. I recommend taking the fish back to your LFS and research how to properly take care of these animals.