[mickmac]

So I bought 5 ember tetras 3 days ago. All alive and fine. They are the only animals so far in my 17g tank. Today one of them has starting bothering all the others — chasing them down. I don’t see any actual contact (but they’re tiny and fast, ?). In reading about this, it seems like a common reason for this is thought to be too few embers, encouraging the little bully to stake out a territory.

I’ve seen a lot of recommendations to add more embers to diffuse the aggression.
I was planning to get at least 6 more, but is it too soon to burden my freshly cycled tank with them? I thought I need to wait a week after adding first few fish, but maybe I should speed up my timeline by a couple of days and get more today?

 

[brendon-]

I have a school of 14 embers, and even with that number they will occasionally chase each other. While they shoal most of the time there are about 4 that like to stick to specific parts of the tank and will briefly chase away any other that tries to intrude on their space. But it’s not very aggressive e. I think a larger number should help. With other tetras I’ve had, they seem to chase each other in a new tank for a few days until they establish their pecking order. If I ever lost one of the dominant fish, they would do it all over again until the order was established again, and then calm down.

 

[mickmac]

That’s interesting, and helpful. Thanks @brendon. The more I read about this today, it does seem like I should get more embers — the bully fish is getting a bit more aggressive, and more schoolmates might diffuse that situation. My question still is whether it’s better to do that tomorrow or the next day, or wait longer for the tank to hit whatever balance it needs to hit before adding more embers. FWIW my ammonia and nitrate levels have been at 0 each day since adding the embers. (Nitrates at 5 ppm).

 

[Fat Guy]

I think you’d be ok adding more, but the aggression/bullying will be there with the ember tetras. they do that. Neons do that. cpds, whiteclouds, a lot of fish will display their dominance in the tank. And only being 17gallons, there really isn’t a lot of places to escape for the ones that are being bullied. It’s not as bad in larger tanks with more swimming space, but in a 60p your space is pretty limited. That’s why I have chosen to keep....well...you know the tetras I keep 😜...emerald eye tetras are cool too...but watching fish bullying others...even if it‘s normal behavior messes with the serenity I’m going for in a planted tank. Hopefully he will chill out but don’t hold your breath

 

[mickmac]

Thank you for the sage words @Fat Guy. How is it that absolutely none of the information I read before buying them mentioned a word about this? It’s all “oh they are such peaceful fish”! ;-D

I actually intended to get cardinals but the LFS had none when I went in. But they had embers, and I had intended to maybe get some anyway, so I caved and went with them instead. So now I’m torn — really working towards a peaceful tank, and not sure what to do now.

 

[Asteroid]

I've never had any aggression out of my embers. And I've had them on different occasions years apart in different setups. They really aren't an aggressive species compared to some other fish. How bad is the aggression. Are fins being torn. I also think once you add another species of fish it will stop, since they'll act as a group where the real (or perceived) that is from the other species.

If all is good, just wait a few days, test your water and you could add something else.

 

[mickmac]

@Asteroid i can’t tell if there’s been any damage — they are so tiny and so fast, too fast for my eyes to see. It was a bit more aggressive this afternoon. The bully seemed to be trying to head butt the others and might’ve been making contact. I’m hoping things will get better but seems unlikely ...

 

[Jack2714]

It is just their way of hierarchy thsg lots of tetras have. They likely will not cause any damage or stress to each other. Just make sure there are enough hiding spaces(or that there will be once everything is grown in). I think if you got some more it would divide this hierarchy up more, but also may take a few weeks for them to get established and then it may go down too... if worst comes to worst you should be able to bring them back and get some different fish

 

[Savetheplants]

When this happened with our Angel Fish. We put the aggressor fish in a plastic isolation box. It gave the victim Angel Fish a break from the abuse but did not correct the aggressive fish's behavior. It seems fish are untrainable when it comes to their aggression. I have expelled aggressive fish from the tank back to the pet store more than once. I just return them without getting a refund and they're gone. Expulsion works until a new aggressor emerges.

 

[Asteroid]

@Asteroid i can’t tell if there’s been any damage — they are so tiny and so fast, too fast for my eyes to see. It was a bit more aggressive this afternoon. The bully seemed to be trying to head butt the others and might’ve been making contact. I’m hoping things will get better but seems unlikely ...

I do think when you add another fish from a different species things might calm down, but as others mentioned embers don't really bully and behave like more territorial fish like cichlids. I added 5 and then eventually got it up to 12 in just a 12 gallon tank and I haven't lost any in over 18 months. I do have black neons with them, which are much larger.

 

[shrimp? fish? CRABS?!?]

ok, first you should get 3 more to even it out to 8, then if you have lots of hiding places (plants etc.) you should really only see them attacking every so often to re establish the pecking order, if you don't have plants or that many hiding places go get some fake plants or something for the mean time. (here's the thing, I only have one tank, it doesn't have embers, I'm a fish keeper with not that much actual experience, but I research fish a lot, so take my advice with a grain of salt)

 

[brendon-]

I think you have enough space in your tank, they are considered a nano fish. They’re also more interesting at larger numbers, and their bio load is so small that I don’t think you’ll notice much of a difference in your water parameters right now if you add more. You may want to add things that break the line-of-site so there are place all around the tank they can retreat to if they want, like large pieces of driftwood. This also looks really nice haha and mimics more of their natural habitat. Not saying much new here compared to others above, but you’d be able to see if one of the fishes fins were actually torn up. If that’s not the case then I wouldn’t worry for the time being.

 

[mickmac]

Thank you all! Today they are looking no more aggressive than yesterday, and maybe a tiny bit less bullying in there. My tank water parameters are all good (7 pH, 0 ammonia, 0 nitrites, and 5 ppm nitrates). I will get 3-5 more embers this week and see how it goes. @brendon- and @shrimp? fish? CRABS?!? i have lots of hiding places and line-of-sight breakers so I think I’m ok on that front. Thanks everyone !