Skip to Content

7 Reasons Your Gourami Fish Is Acting Aggressive In Your Tank!

The number of people keeping gouramis in their aquariums is starting to increase again after the species seemed to fall out of favor with the fish keeping hobby.

We really do love the unique look of the gourami and it’s great to see the various types of gourami starting to increase in popularity again.

As the number of people who keep gourami within the fish keeping hobby continues to increase, the number of people that we see reaching out with various questions about keeping the species in their tanks also increases.

One question that we have seen people asking recently is why their gourami fish is aggressive to its tank mates so we wanted to publish this article going over the most common reasons that your gourami maybe being aggressive.

We hope that this article will be able to help you identify a potential cause of the aggression of your gourami in your tank and help you work out a way to correct the problem moving forward.

Are Gourami Fish Aggressive?

Although most types of gourami are relatively peaceful for the most part, there are a number of issues that can occur in your tank that can increase their aggression levels.

For the most part, this will usually only result in chasing and minimal fin nipping but in bad cases, an otherwise peaceful gourami may end up becoming hyper aggressive towards their tank mates.

This is usually an indication that there is something wrong with the setup of your gourami tank that needs to be corrected and in most cases, if you do fix the problem in the tank of your gourami then you should be able to have your gourami return to being peaceful.

Why Your Gourami Fish Is Being Aggressive!

Here is our short list of why your gourami may be acting aggressive and we will go into more detail for each one later in the article:-

  • Your Tank Is Overstocked!
  • Poor Water Parameters!
  • Food Aggression!
  • Stress And Anxiety!
  • Aggression From Tank Mates!
  • Your Tank Is Too Small!
  • The Fish Is New To Your Tank!

If your gourami is being hyper aggressive then there is a good chance that you probably have more than one issue from the list above in your tank.

Your Tank Is Overstocked!

One of the most common reasons that your gourami may be acting aggressively is simply because your tank is overstocked.

If you have too many fish in your tank then it can quickly become overcrowded and this will put a lot of stress on all of the fish within the aquarium.

This can cause a number of issues such as water quality problems and a decrease in the oxygen levels within the water which can lead to your fish becoming sick and stressed.

When fish become sick and stressed, they are much more likely to become aggressive as their immune system is weakened and they become more territorial as they try to protect themselves.

If you suspect that your tank is overstocked then you should quickly remove some of the fish to another tank or give them away to a friend as this will help to reduce the stress on your gourami and hopefully stop the aggression.

Poor Water Parameters!

Another common reason that your gourami may be acting aggressively is poor water parameters.

If the water in your tank is not clean and has a high ammonia or nitrite level then this can quickly lead to your fish becoming sick.

When fish become sick, they are much more likely to become aggressive and certian water parameters being out of whack can constantly irritate the skin and scales of your fish increasing the chances of them being aggressive to their tank mates.

You can usually fix many of the problems with water parameters by changing 10%-20% of your tank’s water once per week.

Ideally, though, you will be using a water test kit on your aquarium water to get an accurate reading of the potential issues and then working on fixing them.

Another thing that many people new to the fish keeping hobby overlook is that most tap water contains chlorine and the chlorine can irritate your gourami and make it more aggressive.

Thankfully, tap water conditioner products are cheap and easy to use and they quickly fix the issue in your tank by removing the chlorine for you during your water changes with tap water.

Food Aggression!

If you are not providing your gouramis with enough food then they can end up developing issues with food aggression against their tank mates.

This can be common due to so many fish keepers trying to avoid overfeeding their gouramis but hitting the sweet spot of giving just enough food can be difficult to find.

In our opinion, you should tweak the amount of food that you offer your gouramis when feeding them by slightly increasing it until there is food left over on the surface of your tank after five minutes of adding the food to the tank.

This can be a good indicator that you have added too much food to the tank and the fish are not hungry enough to eat it.

Many of our readers will be surprised with just how many people underfeed their fish causing problems with food aggression in their tank.

Stress And Anxiety!

There are a large number of different things that can cause problems with stress and anxiety in your gourami.

Heightened stress and anxiety levels don’t necessarily make your gourami more aggressive and many of them will hide but they will become more irrational in their reactions to some common issues.

This means that if a tank mate swims too close to a stressed or anxious gourami then it may chase or nip the tank mate.

Finding the cause of the stress and then working on removing it will usually prevent this problem moving forward with your gourami in your tank.

Aggression From Tank Mates!

Another reason that your gourami may be acting aggressively is because it is being bullied or harassed by another fish in the tank.

This can be a common issue and one that many people overlook as the aggressor is often much larger than the gourami.

If you have other fish in your tank that are chasing or nipping at your gourami then it is only natural for your gourami to defend itself.

This can be a problem for many beginners though as they usually don’t have additional tanks that they are able to use to separate their gourami from the aggressive tank mate causing the problem.

Your Tank Is Too Small!

A common reason that gouramis may become aggressive is because the tank that they are living in is too small.

Gouramis can grow quite large depending on the species and many people do not provide them with enough space to swim and explore in their tank.

This can cause a number of different problems for your gourami and one of those is aggression.

If you are keeping a gourami in a tank that is too small then we recommend that you either upgrade to a larger tank or rehome the fish to someone with a larger tank.

The Fish Is New To Your Tank!

It is totally natural for a gourami that has only been in a new aquarium for a day or two to have higher levels of aggression due to being in a new environment.

Over the coming days, this should change as the gourami gets used to its new home and calms down.