Small, schooling, reef-safe fish?

[JCM]

That wasn't my intention. My point was, In aquariums some fish will hang out in loose groups occasionally but will often be spread out across the tank. Anthias are probably the best bet. Damselfish may if they don't continually pick off the weakest link. Firefish form pairs as they get older. Cardinalfish are another good option.

None that I have any experience with will keep packed together in a tight group long term.

 

[monkeyCmonkeyDo]

Most ppl shouldnt even keep anthias. Lol. I dont even reccomend them. Same i do not wish to argue only point out that fish do indeed "group" or school if u have enough of that fish and ur tank is big enough say 150+gals.
This is my opinion. I will look up shoal vs. Schooling and do some research yo. Lol.
-d

 

[M Stein]

Not much experience other than having chromis' not school in my father's 75 gal. But my impression is that schooling fish are more likely to school in larger tanks, where they can school without bumping into each other.

 

[Zionas]

I heard even Pajama Cardinals get more territorial though not necessarily aggressive if they split into breeding pairs.

 

[DirectCherry]

Can't go wrong with Seal's Cardinalfish. You can get them captive bred now too

 

[D-Nak]

Blue eyed cardinals actually stick pretty close together. Chromis not so much.

 

[Leo_ian]

blue eye cardinal fish and red stripe cardinalfish and maybe chalk bass

 

[WVNed]

I have seen the posts about chromis from lots of people. I think they act differently in a large tank.
Mine are together almost all the time.

I will say there is some loss from a group of them at first and once you end up with how ever many are left it is almost impossible to add more to the group. The bicolors act like damsels. They were a mistake. They dont swim together at all.

 

[IKD]

I see lots of votes for chromis but has anyone kept a large group for a year+ without them eventually killing each other off? I vote for anthias.

 

[jft]

Chalk bass and tomato clowns are in my tank they hang out together by species very little aggression, all added at same time.

 

[shneerf]

I see lots of votes for chromis but has anyone kept a large group for a year+ without them eventually killing each other off? I vote for anthias.

Nope. Started with 9, ended with 1. They are little jerks. Plenty of room and plenty of food but the main bully will never stop 24/7 until the rest are dead. You can slow this by adding rockwork and places to hide but the betas will live in stress until they die. I now have one big ugly chromi that I want gone. It just keeps attacking any fish that lets it. It killed a young lavender tang I added because they were about the same size. I will never recommend chromis to anyone for any reason. Ugly little jerks.

 

[IKD]

Nope. Started with 9, ended with 1. They are little jerks. Plenty of room and plenty of food but the main bully will never stop 24/7 until the rest are dead. You can slow this by adding rockwork and places to hide but the betas will live in stress until they die. I now have one big ugly chromi that I want gone. It just keeps attacking any fish that lets it. It killed a young lavender tang I added because they were about the same size. I will never recommend chromis to anyone for any reason. Ugly little jerks.

I had the same experience on a smaller scale (5 chromis down to one). I read a few threads with similar experience so surprised there was so many recommendations to this OP to add them. I haven’t had long term success with these

 

[fragit]

Chalk bass are a good choice if introduced at the same time. They will group together, not sure they will school though.

 

[Reefvision]

Green chromis-started with 5 , one passed and one went down overflow and was found alive 3 weeks later . Put it in smaller tank for a month to fatten up. Then it went back into main 220g and all 4 have been fine now 3years.they swim together also.

 

[srobertb]

No fish are going to school in your tank. They exhibit that behavior to avoid predation. When they realize there are no predators in your tank, they won't school.

That said, if I had a 300g I would add a huge group of anthias.

So get a lion fish. That’ll get them schooling.

 

[Rmckoy]

Search mono ….
they are a brackish water fish but can be acclimated to full reef salinity .

ive had them in the passed but keep in mind, they can grow big .
a 300gal would be perfect

 

[BostonReefer300]

I now have 8 blue green chromis in my tank, three from a “1st generation” that was originally 7, and 5 from second gen that was also originally 7. They school/shoal/whatever together all the time in my 300G and visitors always comment on them. You just have to be OK with a “murder period” until their pecking order is figured out. Terrible to say, but at least they’re not expensive—-and this fighting definitely happens in the wild as well. I also have 4 Banggai Cardinals. They stick together sometimes. However I don’t like how they stay stationary so much

 

[Rmckoy]

I now have 8 blue green chromis in my tank, three from a “1st generation” that was originally 7, and 5 from second gen that was also originally 7. They school/shoal/whatever together all the time in my 300G and visitors always comment on them. You just have to be OK with a “murder period” until their pecking order is figured out. Terrible to say, but at least they’re not expensive—-and this fighting definitely happens in the wild as well. I also have 4 Banggai Cardinals. They stick together sometimes. However I don’t like how they stay stationary so much

With chromiss .. there will eventually only be 1 IME
I’ve tried many times adding odd numbers to eventually always end with one sole survivor .

 

[Arabyps]

If you can maintain an appropriate feeding schedule, anthias are among the most beautiful fish (but relatively costly). I only have 3 but they stay together in the middle of the water column and very active swimming about. Mine are Dispar Anthias. Another option are mollies. They can easily be converted to saltwater, occupy the mid to upper water column and hang together. I have 2 black mollies originally purposed as canary fish after a 76 day fallow period. Now they are happy residents.

 

[Robert Riccio]

Resplendent Anthias. They do not get that big and you can also tell the males from the females. These guys are always in a school swimming around.