i bought 10 for a 200 tank. they started killing off even with heavy feeding. 5x per day! im left with 2 pairs and they are in separate tanks. its been about a year. if i reintroduce them together surely death will occur.

Sadly, even in a large system, I have a 10 foot 600 gallon tank. i tried 2 schools on different occasions of blue-green chromis. And I always wound up with one at the end.

Good video. I've never had chromis, but I have heard time after time from folks that have had them, that they are of the mentality that "in the end, there can only be one". Even if I had a massive tank, I doubt that I would ever get any. Maroon clownfish are more than enough of a pain for me.

Excellent informative video. Chromis are in the same family as clowns, bunch of bullies jerks. Love them but these animals are ruthless. I found out when I added a chromis (1) to my 150 that has 3 clowns, they went after him like no tomorrow. Funny though, that chromis is so agile/nimble, he would sidle up to them and scoot away, they could never get him... very satisfying to watch once I knew they couldn't touch him 🙂

I have had 6 of them in a 65 gallon for almost 2 years with some other fish. I feed them heavily with frozen foods and flakes. They bicker, but that's as far as it goes. I have had them in the past, and they would pick each other off one by one.

This was very helpful. I have a 260 gallon glass cages tank and wanted to put 7 green chromis in my tank. I think they would have plenty of room??

I have 10 in a 530L mixed reef tank , had them for 2 years in this tank , a year before that in my frag tank . I feed my fish 4 times a day as have tangs , plus other fish .

Is the coral formation on the left an insert? If so, where did you get it?

I´ve kept 10 chromis in a 500 liter tank for more than 5 years now. I even added 2 more a couple of months ago without any problems. I strongly believe that an aquascape with lots of possibilities to hide increases the chance to keep a healthy, less aggressive school. I also believe that if you keep bigger fish they see as a potential threat it also increases the chance of them sticking together as a school. Moreover, I read that a bigger school results in a broader distribution of aggressive behaviour, meaning less stress for the ones being chased every now and then. But who knows, maybe I was just lucky.

I found if you have a fish timer you can keep them, the day it runs out of food or the battery goes dead, they will kill one off.

What if you keep a packs of chromis and anthias together? Could they be distracted from killing their own?

I had the exact same experience with these fish ! Started with 6 in a 240 gallon reef tank and now a year later there’s 2 I believe these fish should be ban from sale in the aquarium hobby

I'm pretty sure this is something that everyone knows, if you bought them at an LFS they screwed you if they didn't tell you they will take each other out. You ned to have a large school of them, in the past I kept 9 together in a 120 with no problems. It also helps to keep them well fed.

I have 6 chromi’s in my 75 gallon tank with no issues. they are super playful, and not aggressive at all. they LOVE to eat. it amazes me how much mine eat everyday. i think chromis start becoming aggressive and mean when you don’t feed them enough. i feed my tank twice a day, and they are a super healthy school.

LOL I had 5 3 years ago now I have 2 left. My last one bullies the other one still.

Being so paranoid about these fish, I only ever decided to buy a single one. One year later, and she's doing just fine.

Green chromis require heavy feeding, ( 3x a day minimum) and need to be in groups no smaller than 6 or they will become aggressive. My school is fine because I have an auto feeder with pellets that supplements my manual feeding,

do you think 40 gallons is enough for 2 of them or am i crazy?

They don’t school in captivity like in the wild 2 bout as many as I put in a tank together

That’s an idea. Can you introduce a single 1 inch Green Chromis into a tank that already has a single 4 inch chromis and have them pair up like a clown pair does?

That is so true I had 3 now down to 1 on my 75g oh well better then nothing lol

They come in loaded with flukes most of the time.

To be successful you need more than 10, I keep them in schools of 30-50 with no issues of them picking each other off. Problem is most people don’t want to pay the kind of money that this would cost on one type of fish or they wouldn’t house them in a big enough tank in order to keep that many chromis. From the comments, you can see people failing with schools of 10 or less.

I learned this a long time ago. So i purposely only bought one, it's kind of like an angel fish replacement for me, mimicking Genicanthus.

It’s feeding.. they feed constantly all day

Its the biggest mystery in the hobby why the blue green chromis is described as easy and peaceful. Every hobbyist knows they will kill each other off in time. And the last fish remaining never lasts that long as its a schooling fish and in the wild needs companions. It is impossible to keep these unless you have a 250 gallon aquarium. I think domino and Yellowtail damsels which are described as aggressive and semi-aggressive are less dangerous to each other than these chromis.

Have 4 and they killed my copperband butterfly fish

Watch videos or, if you get a chance to go snorkling/diving, you'll see chromis living in schools of hundreds of individuals over a huge expanse of ocean and corals. I think the average fish keeper just don't have the proper size tanks for these guys. I would say I did successfully keep 4 in a 95 gallon. I started with 6 though.