Lemme see your chromis school What’s the trick?

[Doctorgori]

I did do a search here but couldn’t really gleen any new info. I would appreciate it if someone has links to decent threads on keeping chromis …

I’ve attempted the blue-green Pacific chromis at least 6x, always the same results: death from uronema within days or the school murders each other over the next month or so

the dark blue Carribean species seem less disease prone but also more difficult to make a school … they are more tolerant of each other on the one hand but don’t exactly school up either.. These will also pick each other off eventually…best luck I’ve had is with 2 in a big tank

can I see your chromis and what are you doing?
where did you get them?
How long?
what species?

 

[GARRIGA]

Not about getting them to school but how one hobbyist treated his tank and might help with this situation as he was able to eliminate uronema.

 

[Miami Reef]

I still have my starting 12 chromis for almost 2 years. I believe these 3 things are critical to my success:

1) They must be free from uronema
2) You must have a large enough tank
3) Keep a group of lyretail anthias with them


I’ve tried many times to get my chromis to survive QT and I’ve failed until I tried something really weird. I don’t know if this solved the uronema or if it was just a lucky batch. I’ve only ever purchased my chromis from the same holding tank at my LFS.

I dosed ciprofloxacin in the tank daily and gave them Ruby reef rally pro baths. I have no idea if this worked in stopping uronema. I think it had to have an effect.

I personally see my lyretail anthias swooping toward the chromis. I think this behavior prevents the chromis from killing each other.

 

[Doctorgori]

I still have my starting 12 chromis for almost 2 years. I believe these 3 things are critical to my success:

1) They must be free from uronema
2) You must have a large enough tank
3) Keep a group of lyretail anthias with them


I’ve tried many times to get my chromis to survive QT and I’ve failed until I tried something really weird. I don’t know if this solved the uronema or if it was just a lucky batch. I’ve only ever purchased my chromis from the same holding tank at my LFS.

I dosed ciprofloxacin in the tank daily and gave them Ruby reef rally pro baths. I have no idea if this worked in stopping uronema. I think it had to have an effect.
I personally see my lyretail anthias swooping toward the chromis. I think this behavior prevents the chromis from killing each other.

So perhaps a dither species to keep them distracted? That’s certainly plausible, I could see their ranges/habitats certainly overlapping …
I’ve been told by divers the blue carribean type tightly schools when smaller which also makes sense

 

[ISpeakForTheSeas]

No personal experience, but I've looked into a lot of cases where the fish schooled and where they killed each other off, and the below is the list of variables I could come up with that seem to be important (other fish to keep them in line is one of the variables):

My understanding is that keeping a large school can theoretically work, but - as mentioned above - there are a number of things to keep in mind with schooling:

- The number of schooling fish in the tank (I've heard odd numbers are preferred, and the preferred number of fish that I've seen seems to be 9 to 11 at a minimum; the more fish, the more diluted the aggression is between them)

- The size of the tank (for quality of life purposes for your fish, bigger is better - yes, some animals will be calm when shoved into tiny spaces with large numbers of conspecifics where if there was just one or two conspecifics, it would be a deathmatch, but they obviously wouldn't be happy in that situation long-term)

- The amount fed, the quality of the feed, and the frequency of feedings (basically more food = less aggression; and better food = better health = happier, less aggressive fish [theoretically])

- Tankmates (big, scary tankmates that the schooling fish could view as a threat may act as an outside force that keeps the schooling fish focused on not getting killed rather than on fighting amongst themselves)

- The scape of the tank (lots of fish need lots of places to hide/sleep - the more hiding places, the safer the fish feel; line-of-sight-breaks can also help with feeling safe)

That's all I've got for the moment (and pretty much all of it has been mentioned above), but basically - to my understanding - it's a balance of making the fish feel threatened enough by external sources to prevent infighting while also making them feel safe enough (largely through their numbers, the tank's scape, and food security) to not be too stressed. If you're able to strike that balance, you should be able to see schooling behavior (to the best of my current understanding).

Keeping a school of chromis?

I'm looking at a tank upgrade to a much larger tank, and I've always wanted to have a larger (20+) school of green chromis. The issue is, every time I've tried groups of them (3-5) over the years, they inevitably whittle themselves down to 1 Alpha Chromis. Has anyone had luck keeping a school...

www.reef2reef.com

 

[Doctorgori]

appreciate that link!!!!
@ISpeakForTheSeas
I swear I just did a search and missed it

 

[Tub Life]

No real experience yet... I currently have 7 of them in an observation tank, waiting to be released into my display to join the single loner chromis in there currently.

Feedings and larger fish I think will help. Larger fish to "scare" them every now and again so they "school" more for safety. And plenty of feedings to help diminish aggression, yes they are small fish, but they are quite active fish, I'm trying to fatten them up. I see them chasing one another in the observation tank, a 48"L 45 gallon. Some of the chasing and nipping could be due to them trying to establish a hierarchy.

 

[Sully32]

I have had 9 Blue Green Chromis together for 1.5 years without any issues. In fact, the 4 largest ones have formed into two pairs and lay eggs very often. I bought them from 3 different sources. I think a combination of things has made it work for me. They are in a 120 gallon that is heavily stocked. The busy nature of the tank kind of breaks up aggression. I have 3 tangs that chase each other around once in a while and it scares all the Chromis into schooling. My Orchid Dottyback darts at them often. There are also 3 Yellow Tail Damsels and a Pink Smiths Damsel in the tank. So there is a lot of split up aggression. I feed heavily twice a day as well, along with providing Nori, which the Chromis go nuts over.

Terrible pic, but here it is anyway.

 

[CLew]

Years and years ago, I tried repeatedly to maintain a school. I started with ten and they did start killing each other off. When I had only five left, I bought another five to replenish, and they continued to kill each other off. I went through another round of replenishment, maybe two rounds. My group finally settled down to around seven chromis. The one thing I observed about the remaining seven fish was that they were all similarly sized.

When I set up my current tank in 2017, I placed eight chromis in it and I hand-picked them all to be around the same size. I still have seven of them. One is slightly smaller than the rest, and I thought he be killed off eventually, but he's still hanging in there. He's missing scales and looks a little scraggly, but he's tough enough that the others don't bother him anymore. Anyway - maybe sizing them similarly will help?