High aggression among discus

[curtman118]

My questions is regarding an excess amount of aggression in my discus fish.

I recently set up a 55 gallon wide tank exactly a month ago. The first fish I put in the tank were 3 red turqoise (3"), who acclamated well to the tank after about a week or two. There wasn't much chasing until they got more comfortable in the tank. The biggest one started chasing the smaller ones every once in a while, but nothing too bad.

Then, last week I added 3 more discus (a 2" blue diamond, a 3.5" marlboro red, and a 3" gold diamond). These fish acclimated very quickly to the tank and never turned dark in color. However, after a couple days in the tank, chasing/bullying became insane in my tank. It's at the point where I get stressed out watching these fish hase each other constantly around the tank. And it's not just the new fish that are getting chased, aggression among my old three red turqoise doubled.

I thought discus were supposed to be peaceful schooling fish????

At this point, the three new fish have taken to hiding under the filter behind a plant most of the time, and when they come out once in a while they quickly get chased back in there by any of the red turqoise fish. The new fish have been in the tank about 5 days. My red turqoise still hang out in the front of the tank and swim around together, just with much more chasing than before.

Once my new fish get more used to the tank will they stand up for themselves? Or is this going to become a problem?

Please help, I can't even enjoy my fish when they're either hiding or chasinsg each other around.

[Ryan]

Discus are peaceful fish, but they are also cichlids, which means that there will be a certain level of aggression between individuals in a group. It's similar to the hierarchy of a wolf pack -- each fish has a rank.

The fewer discus you have, the worse the aggression is. This is why it's best to always start with 6 fish. Anything less than that usually leads to problems, especially if you only have 2 or 3 fish. For the aggression to be spread out fairly evenly, 6 fish is best.

In this case, your 3 discus got comfortable in the tank and established themselves as the only discus in the tank. The addition of 3 new fish upset that balance, and now the original fish are trying to establish their dominance over the newcomers.

What has to happen now is that all 6 fish have to establish their place in the pecking order. There will be bickering and fighting until that happens. My suggestion is to pull ALL the fish and put them in QT tanks or buckets, then re-arrange a few decorations or something in the tank, then add them all back at the same time. This usually disorients them and makes them all think they're in a new place. That puts everyone on equal ground, so to speak.

It doesn't always work, but it can. You may also buy a cheap divider and separate the new fish until they are strong and eating well, then try and acclimate them like I described above. Stress from being moved to a new tank, added to stress from being harassed by other discus, could lead to secondary issues with your new discus (like hex).

Keep in mind that if you add a divider, the aggression between the 3 original fish might continue to escalate. I'd try pulling them all, then re-adding them and see if it calms them down and gives everyone an equal chance.

Ryan

[curtman118]

Thanks for the advice Ryan. That sounds like what I have been hearing from other people. I think I might try taking all of the fish out and re-arranging the tank this weekend when I clean the tank. One thing though, the three new fish are looking healthy and eating just as much food as the three fish that were already in the tank. During feeding time they are just as aggressive as any of the other fish. So it seems as though they are acclimated and happy, but are still being bullied. Regardless, I guess my hree original fish think that they own the tank so the health of the three new fish must not matter all that much.

Do you think this bullying will stop without having to take all the fish out? Will they figure out a hierarchy in time?

[Ryan]

Well, with any cichlid I always observe the fish and make decisions based on what I see. If the fish are just being chased and nipped at, and they don't seem to mind, it may resolve itself.

If the aggression is so bad that the new fish are being physically attacked, or if the original fish won't let the new fish come out from hiding, then it may require an intervention on your part.

I guess what I mean is that if I feel that my fishes' health is at risk because of stress or injury, I would step in and split them up and try to resolve it that way. But if they don't seem that bothered by it and everyone's eating and in good spirits, I'd just sit back and observe for now.

Like your original three, these will get more comfortable over the course of the next few weeks... they'll be a little bolder, a little less passive. They will take their place in the pecking order and start showing the others who's boss.

Ryan

[curtman118]

Ok, great advice. I don't think the fish are actually hurting each other, but there is a lot of nipping and chasing around the tank. The three new fish are quick to run back to their hiding place after being chased.

One more thing: what is a normal amount of chasing/nipping once discus are settled in? Ideally I would like the fish to be able to all school together peacefully with maybe a nip every once in a while without any extreme chasing. Is this unrealistic to hope for because discus are cichlids? Would it be best to get maybe three more discus to try to mitigate the aggression among the fish? Also, is there any reason to think that water quality/stress would cause this type of behavior?

[Ryan]

Actually, adding more would probably just add to the chaos. It'd be yet another set of unfamiliar discus for your original fish to harass. I think the number you have, especially with your size tank, is plenty for now.

Once everyone gets settled, there will be squabbles and nips but it probably won't be that way all the time. My fish are 3.5" - 4" standard length (nose to base of tail, not tip of tail) and the only time I really see fighting is during feeding time.

I would think that everyone would mellow out after the initial acclimation. I guess it depends a lot on each fishes' personality, though.

Be warned... as they go into their "teenage" years when they start to sexually mature, things will go to hell basically. Chasing, tail-slapping, stand-offs between males, males trying to impress the ladies, etc. Compared to that, this is nothing. lol.

[curtman118]

Would adding fish, like cardinal tetras, do anything about the aggression?

Oh, and about the hardcore fighting in teenage years...perfect, that's just what I wanted to hear...lol. What are you supposed to do at that point? Start removing fish?

[Ryan]

I never really removed fish. If they pair off, some people choose to separate them and put them into breeding tanks. That's not really necessary though. You'll find that even though they fight and argue, it's usually not violent and in most cases you can just leave them alone. It's actually pretty interesting to watch. You get to see all your discus' personalities.

Dither fish really don't do much. If you read the Tankmates section here, you'll see that most people report their discus ignoring tankmates basically. They'll still have the pecking order with the other discus.

I think you'll see less aggression once your fish settle in and get to know one another. The first few weeks is always a turbulent, gut-wrenching experience for new discus owners. It'll pass.

[curtman118]

Ok. That's actually great to hear. Until now, all I had heard about was the peaceful slow swimming of discus and how nice it was to watch them. It's good to hear that discus actually can be fairly aggressive when figuring out a tank hierarchy. Thanks again for the excellent advice...now back to homework..

[April]

id take out all the plants..and then no hiding. but first throw them all in a bucket and re-ad them to the tank all at the same time as ryan said.
maybe they already are in their teenage years. how big are they?
remember..buying fish from different sources can be a disaster waiting to happen without quarantining.
dont buy more..your tanks too small for more than that.
do big daily wcs for awhile..get them used to you working around them etc.
sometimes..if your ph drops quite low..it does make them more aggressive.

[EyeOfThierry]

A low PH can make the Discus aggressive? really? How low are you talking about?

Also, I have 2 adults and 2 juv. in my 55gal tank. i had the adults in their own breeding tanks till i found out they were same sex.... then placed them back to the 55. I would have left adults in the breeder, since they seemed happy there and i had no alternate discus ready for matchup, but the 2 juvies were always hiding. they were by themselves (with other community fish, tetras, and cards). since i've added the adults, the juvies don't hide anymore... but the smaller of the juv keeps getting chased into the hiding space by the larger.

i find that the small one doesn't eat enough. What can i do to fix things? I was hoping to get two more juvies soon. Would that help? there is definitely a pecking order right now... the adults are nipping at the large juv, and the large juv does the same to the small one... but i don't want to wind up with a stunted fish!! I call the juvies twins cause the are exactly alike, but starting to get diff in size because of food quantity eatin.

i've tried in the past to divide the tank, but all that happens is the small juv jumps over the divider... it's quite fiesty and doesn't like to be alone...lol.

-T

[April]

well thats your problem. whether your two adult fish are the same sex or not..they seem to think they are a couple..and they dont want those rugrats around.
or put a divider.

[EyeOfThierry]

well prior to the adults being there things were worse. they both were not eating, and they were hiding. Now they come out, but the small juvie is suppressed.

[tgirl6868]

Be warned... as they go into their "teenage" years when they start to sexually mature, things will go to hell basically. Chasing, tail-slapping, stand-offs between males, males trying to impress the ladies, etc. Compared to that, this is nothing. lol.[/QUOTE]

That was good, I liked that. When do Discus become a teenager? At what age is it that they are considered a teen?

[curtman118]

Ryan Smith you are a genius. A god among men. I dubiously took your advice about taking each fish out and puting them in separate containers and then re-arranging all the plants within the tank. I did this a couple of hours ago and after re-acclimating to the tank, all of my discus are now in a happy school! All six of them are inseparable its ridiculous! They're all calmly, slowly swimming around the tank in a group. I'm loving life right now. Thanks Ryan. No more stress when watchcing my discus!! Hopefully they'll stay this way.