last night i made my first post showing my tank that is about 3 weeks into its cycle. every thing was fine last night and when i left this morning. i got home and my nimbochromis venustus is barely clinging to life. he look slike one side of his body was scraped across concrete but the other side looks fine. what could have caused this? aggression? the water parameters are about the same as they were last night. btw the other 2 cichlids look fine. i have not seen any fighting since i got them.