Talk to me about Blue Green Reef Chromis

[lkoechle]

If I want to keep 3 to 5 of them in a 25 gallon (for this argument, species only tank, no other fish), will they still pick each other off?  Why do they do that when they're naturally a schooling fish?  Will they still pick each other off in a large system with similar fish/space ratio?  How do you not get them to not kill each other?

 

I'm looking for actual experience on this one since I know all the "general" rules and stories.  I want to know what people have actually observed and experienced and their take away on it.

[rosecity]

I have 3 of them in a 20 long with 2 clownfish and a single yellowtail damsel. Never had any issues with them picking themselves off or anyone else. The pecking order in this tank is clownfish<damsel<chromis.

 

The three chromis have established their own pecking order within the group. One has grown very large, then there is a middle sized fish, and then a runt. They all eat the same amount so must be some other factor determining their size. They all hang out together during the day and swim back and forth the 30". At night they split up and find their own spots to sleep.

[GregEmmitte]

I'm notorious for slightly overstocking. But I kept 6 damsels and a clown in a 32 gallon. Damsels including 2 blue chromis.

[lkoechle]

1 hour ago, GregEmmitte said:

I'm notorious for slightly overstocking. But I kept 6 damsels and a clown in a 32 gallon. Damsels including 2 blue chromis.

how long did that last?

 

1 hour ago, rosecity said:

I have 3 of them in a 20 long with 2 clownfish and a single yellowtail damsel. Never had any issues with them picking themselves off or anyone else. The pecking order in this tank is clownfish<damsel<chromis.

 

The three chromis have established their own pecking order within the group. One has grown very large, then there is a middle sized fish, and then a runt. They all eat the same amount so must be some other factor determining their size. They all hang out together during the day and swim back and forth the 30". At night they split up and find their own spots to sleep.

How long have you had them for?

[GregEmmitte]

6 months. They're in a 60 gallon now though.

[RayWhisperer]

It must be something with these 2. I've never seen them go more than a year in any size tank.

 

also, they aren't a "schooling" fish, they are a "shoaling" fish. There is a difference. Schooling implies they are more like one unit. Shoaling is more loosely structured, and each fish almost has its own territory.

[Nixperience]

I've heard that they are shoaling fish, which means, in the wild they will clump together for protection from predators, but not stay together all the time like a schooling fish. In a tank, they are forced to be close together, never getting the space they need. Just a thought, but I have no experience with them. 

[lkoechle]

9 hours ago, Nixperience said:

I've heard that they are shoaling fish, which means, in the wild they will clump together for protection from predators, but not stay together all the time like a schooling fish. In a tank, they are forced to be close together, never getting the space they need. Just a thought, but I have no experience with them. 

Yeah I have been reading they are peaceful if you keep them with larger more aggressive fish so they start playing "The enemy of my enemy is my friend" and would rather live in numbers than kill each other off.

[Boggers]

I started with 5 and ended with 2 after a year in a 75G. They just tended to butt the smallest away when food came in that they slowly dropped in numbers over a long time. It was not fighting as much as casing away the smaller one when food came.

[Ebn]

In a species specific tank, yes, they will most likely pick each other off as they mature. They're not naturally a schooling fish, but a shoaling fish. To get them to not kill each other you will need another species which will keep them in check as far as aggression is concerned. With a more aggressive species in the tank, they kind of stick closer together and not wage war on each other. 

 

I started out with 5 of these guys in my 47G tank. Over time, a trio survived from these initial 5. Two larger fish and one smaller one. They were kept with other ventralis anthias and other fish which weren't aggressive. I then later added 5 to the group to beef up their numbers but then over time they started to pick on one another and we're now back down to 3 again. These 3 still attack each other every once in awhile, but I finally got some bimaculatus anthias. These guys rule the tank and will attack the chromis if they stray too far from each other. They spend more time together now then they did before thanks to the bimacs. 

[rosecity]

On 6/15/2017 at 5:55 PM, lkoechle said:

how long did that last?

 

How long have you had them for?

I have had mine for 4 years now. The Chromis and damsel were added to the tank about 18 months after the clowns. Chromis are great if you want to see alot of action. The clowns tend to hang around just a few spots and the yellow tail damsel is not very active either. The Chromis swim back and forth all day long.