10 Little, 9 Little, 8 Little Chromis ....

[kmbyrnes]

I have 6 Blue Green Chromis in my 110 reef tank. I started with 10 on 12/28, and the weaker ones disappeared until things stabilized at the current count on 1/25.
In the past few weeks 3 of them have begun hiding by the powerheads and behind my overflow. They come out to eat, but no longer shoal as as group the way they used to. It started with one in hiding, then a second, now today a third. The most recent additions are a Lubbock's and a Redfin Fairy wrasse added 4/20, but I have never seen the wrasses harassing them.
Everyone else is doing well and all the fish are eating, it's just that 3 of the chromis are out of sight.

Any idea what is going on?

Parameters:
Temp 80.5
Salinity 1.025
ph 7.8
Ammonia 0
Nitrite 0
Nitrate 0
Phosphate 0.5
Alkalinity 8
Calcium 520
Magnesium 1260

 

[snorvich]

Sure. Eventually you will likely end up with one. The dominant one will take out the remainder in almost all cases. There are exceptions to this but those are few.

 

[Triggerfish]

yup seems to be the norm. sometimes you dont even witness what's going on then before you know their wimpering in the corner or missing.

 

[Dmorty217]

Sure. Eventually you will likely end up with one. The dominant one will take out the remainder in almost all cases. There are exceptions to this but those are few.

+1 I started with 25 and ultimately got rid of the 9 that made it a yr from my tank.

 

[kmbyrnes]

Shoot.
Most of what I had read was they would stabilize at about 5.
I thought I was doing OK with a steady number for so long.
Guess I'll have to talk the wife into another tank......

 

[kjamaya]

I've always been told you multiply however many chromis you want in a tank by 4 and thats how many you will run through before you have what you want.

 

[Dmorty217]

They are hardly worth the 3$ each and hassle of netting one dead chromis out of your tank every few wks. It happened for me like this... One would break from the school and hang by itself for a wk or so then it would disappear, a few wks later another would do the same thing

 

[ca1ore]

Sure. Eventually you will likely end up with one. The dominant one will take out the remainder in almost all cases. There are exceptions to this but those are few.

I actually have managed to stabilize at a pair. No idea how, as always in the past is was just one. Two of them really go at it though.

 

[pontiac]

welcome to the world of chromis ownership happens like that to all who have tried that ive seen

 

[Baldguy]

And in a few weeks someone else will post wondering what's happening to their chromis.

 

[Terra Ferma]

Ancient history, but for a while (some time ago) I had a nice school for 18 or so Chromis viridis going for over a year. Sold them to a guy that I think kept them going for quite a while after that. My thoughts:

Start with about 2x what you want to end up with, if you start out with small ones. They are often collected with cyanide out of coral heads. And shipped in bags so small you wouldn't believe...they don't come in that robust (unless you bone out for the larger Tahitian ones).

Feed them often. In nature they are plucking plankton out of the water all day. When they only get 1-2 feedings per day they get grumpy. And when they are hungry and see another chromis snatch their meal...even more grumpy.

Keep them in in a school size proportional to your tank size. I kept the 18 in a 65 galllon, and they went on to do well in a 90 gallon. 1) They don't seem to school if you don't have enough relative to tank size, and 2) Not unlike african cichlids, a critical mass numbers wise spreads out the aggression (which we are trying to avoid by keeping them fat and happy).

You mileage may vary - this is what worked for me. Nothing finer IMO than a beautiful fish that truly schools when done right and is small enough to be kept as a school in relatively small tanks.