Some of the ways you can deal with aggression in your discus fish tank include spreading their food around the tank instead of it being concentrated in a particular area, avoiding overpopulation of the tank, and separating the weaker discus from the bullies.
Table of Contents
- Why Is My Discus So Aggressive?
- How To Solve Discus Aggression And Bullying
- Related Questions
Why Is My Discus So Aggressive?
Although discus fishes are generally believed to be very calm and gentle in nature, it is not uncommon that fish breeders have found their discus fishes displaying a certain level of aggression in the aquarium.
Discus fishes are a kind of fish that flourish when they are in the company of other discus fishes.
So, if one should ask, are discus fishes aggressive? The answer is yes and no, it is not that discus is an aggressive breed of fishes, it is just that they can display signs of aggression under certain conditions.
7 Reasons Behind Discus Aggression
There are seven major reasons that will cause Discus (our gentle-natured cichlids) to display aggressive behaviors, they are:
- Tank Domination.
- Tank or Aquarium Condition.
- Breeding Time
- Feeding Time.
- Different Discus Sizes.
 – Tank Domination
A discus needs to be in the company of other discus fishes to thrive in the tank.
Like every other kind of cichlid, one of them has to be like the ‘boss’ of the others – the one who goes like, “this is my territory and you cannot move until I say so.” Once one of your discus fishes makes others subservient to him, it usually gets to eat food first before the others and so on.
 – Tank or Aquarium Condition
Discus fishes could become aggressive and begin to fight if the condition of the tank is not favorable to your discus fishes. A proper aquarium should have good lighting, plants; especially driftwood (driftwood maintains water pH), and areas where discus could hide since they are very jumpy in nature. If the water quality – pH, temperature – in the tank reduces below what the discus prefers they might become aggressive.
 – Malnutrition
When discus is not getting enough food, there is a great tendency for them to become violent and aggressive. The strong have always dominated the weak, therefore stronger or more mature discus will not make it easy for the weaker ones to get food easily.
So, when you find your discus pecking on each other, not getting enough food could be a reason.
 – Breeding Time
When you have Discus in your tank, a time will come when they will start pairing up for mating purposes. Usually, when two discus fishes pair up, they become aggressive towards the others in the tank because they would try to secure any region in the tank where the female discus could lay her eggs and keep it protected.
Specifically, the male discus becomes aggressive in a bid to protect their mates from other male fishes, whereas the females become extremely guarded when it comes to the eggs they lay.
 – Overpopulation
If you want to have more than 10 discus fishes in one tank, you should ensure that the tank is a really big one.
In the first point above, I stressed that you can find Discus chasing each other for territory, this is especially serious if the space in the tank is not large enough.
Territorial discus wants a lot of space and they would not take it lightly if they find other discus fishes encroaching in their territory.
 – Feeding Time
At feeding time, Discus fish tend to become aggressive with each other and this is very normal behavior based on their natural instincts especially when you feed them blood worms or Beefheart.
 – Different Discus Sizes
It is recommended to have at least 5 to 6 Discus in your tank, also recommended to have them all of the same body sizes, because adding smaller Discus fish with the majority bigger size will cause the majority of the bigger ones to bully the smaller ones.
How To Solve Discus Aggression And Bullying
Discus fishes, pecking on one another (nipping) can lead to health problems in the tank. When the injuries on the wounded discus fish become infected, the disease could even spread to the other fishes.
7 Tips How To Stop Discus Fish Bullying
To stop Discus aggression and bullying, apply the below solutions:
- Spread Food All Around The Tank.
- Aquascaping The Tank.
- Avoid Too Deep A Substrate Bed.
- Change Your Tank Water Regularly.
- Separate The Aggressive Discus From The Weaker Ones.
- Amend Decoration.
- Keep Discus In Bigger Group.
 – Spread Food All Around The Tank
This is very important because it will reduce the rate at which discus fight each other especially if there is already one or more in the aquarium who have marked certain areas as their territory.
When you place food in a single area and it happens that the particular spot has been marked by an aggressive discus fish, the other fishes in the tank will not be able to feed and if that continues for a long period of time, they could die of malnutrition.
 – Aquascaping The Tank
When decorating your aquarium, keep in mind that aggressive behavior could be depicted in the tank and you need to make provisions for that. Your aquarium should therefore have a lot of gravels in it.
You should have a lot of driftwood in your aquarium as well – this will make it easy for discus fishes to map out their territories. Besides creating territories for the various discus fishes in your tank, driftwood can give your aquarium a beautiful look.
Having a lot of plants that could serve as cover for weaker discus against aggressive ones is necessary in the tank. Your discus fishes could hide behind those plants whenever they are being chased around by bigger ones.
Of course, the idea of aquascaping your tank will take a lot of time to get right – you will have to keep doing things to find out what works.
 – Avoid Too Deep A Substrate Bed
Ensure that the substrate you use in your aquarium is not too deep. It does not matter whether you are using soil, gravel or both as substrate, keep the depth at 2 inches. The reason for this is so that when you want to clean out your tank, you will find it easy to remove debris or waste from a substrate of that (2 inches) depth rather than one that is at 4 inches.
 – Change Your Tank Water Regularly
Although this is done for many reasons especially one which makes the aquarium a conducive environment for your discus fishes, changing your tank water daily also plays a role in decreasing aggression in the tank. It is just as important as all the other tips for reducing aggression in a discus tank.
In a stressful environment, it is not uncommon to find discus attacking each other. Clean aquarium water means that your stronger (more mature) discus fish will be less inclined to display any aggressive tendencies toward the weaker ones.
 – Separate The Aggressive Discus From The Weaker Ones
Use a divider to separate the weaker discus in the tank from the aggressive ones. Although if this is done, there is still a chance that the discus fishes that are kept together could start fighting each other for territory or food. The strong will dominate the weak and a pecking order will be established.
 – Amend Decoration
From time to time, modifying your aqua scaping design and play decorations around should definitely reset the territories assigned by some Discus in the tank, and keeping your Discus fish in a new environment will always reduce their aggression.
 – Keep Discus In Bigger Group
As I always say on the Discus Rescue website, Discus should be kept in a group of at least 5 to 6 Discus in one tank, however, if you have a big enough Discus tank, you better increase this number of Discus which should lead eventually to reduce aggressiveness between them.
Here is a nice video talking about Discus aggression.
Why Is My Discus Fighting?
There are many reasons why Discus could be fighting each other, they include poor conditions in the tank’s water, territory, malnutrition, breeding time, and overpopulation.
Among all the cichlids, discus fishes are the gentlest. However, they tend to display aggressive behaviors occasionally. The reasons for this may include shortage of food, overpopulation, poor tank water conditions, tank domination, and breeding time.
Some of the ways to prevent aggression is to spread food around the tank rather than placing food in a single spot, separating weaker discus from stronger ones, changing the tank water, cleaning of the tank, and aquascaping.
One thought on “How Do You Deal With Aggressive Discus Fish? – [ANSWERED]”
I have a 75 gal. Tank with 5 discus and 2 Plecos . Two of the five discus were just recently added. For whatever reason they were not eating. I raised the temp to ninety degrees and after a few days they started eating . So after four days I lowered the temp to 86 . That’s when the red panda discus became aggressive. I will try to raise the ph and hope the aggressiveness will stop. I had changed the aquascape just before I raised temp. At first it seem to help but not for long.if there’s any advice that can help I would appreciate it. Thanks