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Fish, much like their human keepers, can experience a certain amount of stress. Unfortunately, stress can cause the eventual death of a fish, so it is important to ensure that your home aquarium tenant is carefully treated if it is starting to appear stressed.

How to Calm Down Stressed Fish – 8 Tips to Reduce Fish Stress:

  1. Keep nitrate and ammonia levels in the water low,
  2. Get the right sized tank,
  3. Ensure water temperature is consistent,
  4. Set a decent feeding schedule in place,
  5. Implement a reliable filtration system,
  6. Decorate the tank strategically,
  7. Treat signs of infection and disease promptly,
  8. Ensure fish compatibility.

Providing your fish with a healthy environment is the first step towards providing a stress-free life for your pet fish. Various things trigger stress in fish, so knowing how to create a reduced-stress environment is a key element in caring for a potentially stressed aquarium pet. The first step, however, is determining if your fish is in fact stressed.

Symptoms of Stressed Fish

Is your fish stressed? If you notice the following symptoms, chances are that it is. You should take immediate action if you notice that your fish is:

  • Swimming up against things (brushing against décor)
  • Hiding away more than normal
  • Disinterested in food
  • Swimming around manically
  • Struggling to breathe (gasping for air)
  • Crashing while swimming
  • Fading in color
  • Showing spots, specks, lines, or streaking on the body
  • Showing legions on its body

How to Reduce Fish Stress | Saving Fish the Discomfort of Stress

The abovementioned tips on caring for stressed fish above are explained in more detail below.

1. Keep nitrate and ammonia levels in the water low.

Fish are sensitive to nitrate and ammonia in their tank water. Ammonia and nitrate are a direct result of waste build-up in the tank. The only way to ensure that these levels are kept low is to change the tank water regularly and to ensure that you keep the tank clean and toxin-free. Setting a regular cleaning schedule can help to make tank cleaning a habit instead of a chore. There are some water conditioners that you can also add to the water, which help to remove toxins and reduce fish stress. If your fish are living in a build-up of their own waste, they will feel stressed and may even develop diseases.

2. Get the right sized tank.

Just like humans, fish can be social but they also like a bit of space. This is why tank size is so important. If you overcrowd your tank, your fish will start to feel stressed. You will also find that your tank is harder to keep clean and healthy when it is overcrowded. The general rule of thumb is to provide one gallon of water per one inch of fish. If you are unsure about the suitability of your tank size, it is important to discuss this with your local pet store or the person you are buying your fish from. Find out how much space the fish species you are getting needs.

3. Ensure water temperature is consistent.

Changes in the water temperature can be quite stressful to fish. New fish keepers often do not know that temperature fluctuations can negatively impact the immune systems of fish. And when the immune system is low, the fish is at risk of suffering diseases or infections. It is difficult to cite an exact water temperature to aim for as each fish species will have different temperature requirements. Goldfish, for instance, do well in water temperatures of between 68 degrees Fahrenheit and 72 degrees Fahrenheit. Other fish types require a warmer water temperature. Fish that are stressed from water temperature changes usually show it physically. In water that is too cold, the fish may seem lethargic and disinterested in food. In water that is too hot, fish may seem manic and swim around aggressively. To treat a fish stressed by the wrong water temperature, slowly adjust your aquarium water temperature to the correct heat. You should see a somewhat quick change in the fish’ stress levels. When buying new fish, chat to the breeder or pet store owner about the water temperature requirements of the fish and see if this matches up with the requirements of your current fish community.

4. Set a decent feeding schedule in place.

How you feed your fish could stress them out, especially if it is sporadic or irregular. Fish may get stressed if they feel they do not get enough food or if there is too much competition for food. To ensure that your fish never feels stressed about food supply, set a daily feeding schedule in place and try to stick to it closely. You should feel a sufficient amount of food once or twice a day depending on the fish type. You can also make things less stressful by feeding fish at the same time each day. They will soon settle into the schedule and start to feel more secure about food. If you notice that certain fish are becoming aggressive with others about food, you might need to separate them into different tanks. The aggression will undoubtedly be stressful for the more timid fish species.

5. Implement a reliable filtration system.

Aquarium filtration is an essential part of setting up a home aquarium for the first time. The build-up of bacteria and debris in the tank can be stressful to fish as the water becomes dirty and oxygen levels lower. Filtration systems are required to help remove bacteria, debris, and waste products while oxygenating the water, which makes for a healthier and happier living environment for fish. The water in the home aquarium should be filtered through the system several times before you introduce new fish to the tank. If the filtration system is overloaded with waste to clean, hold off on getting new fish. You may need a new filtration system or a bigger tank.

6. Decorate the tank strategically.

Plants, rocks, gravel, and various ornaments are not just for aesthetics, but actually to help keep fish relaxed, calm, and comfortable. Fish that feel that there is no private place to hide or rest will become stressed. The more places your fish can dart into and hide, the more secure your fish will feel. You can use live plants or plastic plants to decorate the tank – just do not overdo it as a cluttered tank can have the opposite effect on your fish and cause stress levels to rise. If you incorporate live plants, just keep an eye on them as sometimes they rot. Dead leaves should be removed from the tank immediately to ensure that they do not contaminate the water or clog up the filtration system.

Colorful Clown Loach Fish – Botia macracanthus

7. Treat signs of infection and disease promptly.

There are several tank diseases and conditions that can stress a fish. It is important to know what to look for and to act promptly when you suspect there is a disease or infection at play. Some of the common diseases and health issues to be aware of include:

  • Anchor worms – are present in the form of green and white threads on the skin of the fish. A fish that seems to be brushing purposefully up against tank décor may have Anchor worms.
  • Body Fluke flatworms – this infection shows up in the form of mucus covering the body of the fish.
  • Dropsy – this is a type of fish kidney infection and presents itself in the form of bloating or the appearance of scales sticking out.
  • Ich – this presents in the form of white specks over the body of the fish. If you notice white spots paired with the appearance of your fish struggling to breathe, it could have ich.

Make sure that you clean the tank immediately and get treatment as soon as possible if you notice any of these diseases. Treating diseases in home aquariums requires a consultation with your local vet or pet shop owner (or fish breeder).

8. Ensure fish compatibility.

If you are new to fish keeping you might not be aware that not all fish get along. Even if they seem to be the same size and of the same temperament, some types just do not get along – much like humans. Before you buy new fish for your community tank, make sure that the species are compatible. Introducing fish species that do not get along can result in serious stress for both fish types. Even if you pair one timid fish species with an aggressive fish, chances are that the experience will be fairly stressful for the timid fish (even though it does not attack or show aggressive behavior towards the dominant fish). It is important to discuss fish compatibility with the pet store or the fish breeder before you go home with any new fish.

Last Words

It can be stressful trying to care for a stressed fish. One thing to remember is that when a fish is stressed, there are several things you can do to turn the situation around. Follow the steps and tips above to care for your stressed pet effectively.


Hi, my name is Jordan. I've been in the fishkeeping hobby since my childhood. Welcome to my blog where I help fishkeepers enjoy the hobby by offering free guides, advice, & product reviews. Read more...