I am currently stocking my Cichlid tank and I'll admit I'm a bit of a newbie when it comes to owning multiple Cichlids. For a bit of a back story I originally had a 35 Gallon with a Pleco, Raphael Catfish, Rainbow Shark, and a Green Severum. Everyone started getting big so I decided to upgrade tanks and came into across an absolutely stellar deal on a 110 gallon tank. THis tank is one of the tall variants (only 4 feet long) so it is not ideal but it is still a great tank.
I let the water cycle with those 4 fish for about 3 months and I'm finally looking to go ahead and start stocking the tank. After doing some research I decided I want to go completely with fish that are "Semi-aggressive" (outside of the Raphael but his name is Clint Eastwood and he fits the part). I bought a Tiger Oscar and then a Geophagus. After some more research I found that Geophagus get really stressed when there isn't sand in the tank, and my tank is only gravel, so I swapped him out for a Fire mouth and a Green Terror.
This was about a week ago and things were fine except now the aggression is starting to ramp up. The tiger oscar is about 4 inches, the fire mouth is about 3 inches and the green terror is about 2 inches. The Severum is fully grown but she pretty much keeps to herself and really isn't taking part in the current power struggles. The fire mouth is chasing the Tiger oscar pretty regularly, and I can tell that the fish is stressed as it isn't as jubilant as it normally is (my wife absolutely fell in love with this fish because of how excitable and cute he is. Will break her heart if he dies from stress!). The fire belly gets chased by the tiger shark occasionally (I'm guessing in response to the Fire belly attempting to bully it and that not flying), and the green terror gets chased by everyone because of his size. The terror is small and smart enough to take cover however and doesn't seem overly stressed (there are a number of caves and a large drift wood piece), while the tiger oscar isn't.
I have a few questions. One is - How much chasing can a Cichlid take before it threatens its life? I'm super surprised the Tiger Oscar isn't fighting back as I really feel like he is the stronger fish! I'm not opposed to taking the Fire Belly back and swapping it for another one in the hopes that I get a less aggressive one, but I feel as though these are normal issues for a Cichlid tank. I've dropped the tank temperature to about 75 degrees from 78 in the hopes of calming everyone down a bit, but I can tell the Oscar is stressed. I feel as though if he can get used to the bullying the Oscar will eventually be in good shape as he should grow faster and bigger than the Fire belly, but its moot if he dies from stress getting there.
I've read that you should over stock Cichlid tanks to spread the hate and have a wide variety of fish to get chased. Should I add more fish? I know that a 110 can technically support more than what I have, but honestly not much more once everyone is fully grown. Also as it is the taller variant I'm hesitant to add many more fish. I was thinking maybe a few silver dollars? How quickly do I need to act? I know community fish die fairly quickly to stress related health problems but I don't know how long Cichlids can deal with it.
Any recommendations would be appreciated!
I'm thinking maybe some Dither Fish might be a good idea. Maybe a school of Giant Danios? I'm worried about spiking the ammonia in the tank adding all these guys so quickly but that might be the best idea. I've also uploaded a terrible quality YouTube video in case anyone would like to see it. Probably should have reshot it with the flash off and calling the fish a Fire mouth instead of Fire Belly, but it'll do!