Meta Description- Learn about how to help fish that are under stress. Know the real reason behind fish stressing out and how to prevent it.
You recently bought an aquarium. You are pretty happy that now you will also have pet fish. You set up the aquarium, cleaned it accordingly, and filled it up with fresh water. Finally, you let your fish inside the aquarium.
But suddenly, after some days, you realize that something is amiss. Your fish is behaving abnormally. This behavior pattern is different from its usual pattern. If that’s the case, then maybe your fish is stressed out.
Don’t stress over this issue. We are going to help you out in this regard. Fish stress is a somewhat common phenomenon. Just like humans, fish can also get stressed.
Even if your fish seems fine, you should take precautions. If it’s stressed, you should solve the probable cause. We’ll learn how to help stressed fish now. We’ll also talk about what precautions we can take.
Let’s start.
What Causes Fish Stress.
Sometimes we think fish are very happy. They’re well fed, safe, and cared for. What we don’t know is that they’re very fragile.
Stress can happen for a lot of reasons. Let’s look at a few of them.

1. High Nitride and Ammonia level
Ammonia and Nitrite can stress your fish. Fish can get stressed if there’s too much ammonia and nitrite in the water.
Infrequent water changes can cause this. If your filter doesn’t work or isn’t replaced, that might be why.
Ammonia levels can cause severe physical symptoms. The fish can die pretty quickly. So you need to keep ammonia and nitrite levels low.
2. Wrong pH level
Your fish can be stressed if the pH level is wrong. Different fish can handle different pH levels. If you introduce different pH levels to them, they won’t take it.
Fish can also get stressed by fluctuations in pH levels. It didn’t matter if it was in an acceptable range or not. Try to keep the water pH level constant.

3. Hostile tank mates
Your fish will be stressed if their tank mates are hostile. When other fish are bigger or dominant, your fish will always be on guard.
Stress can only last a short time for your fish. It can’t handle continuous pressure from them. Your fish will soon be sick and die.
Ensure that other fish aren’t aggressive and dominant. Keep similar fishes together.
4. Wrong Temperature
Temperature is another factor that stresses fish. Just like pH, water temperature also plays a role.
Different fish species can handle different water temperatures. Make sure your water temperature doesn’t fluctuate too much.
5. Less Feeding
Stress happens if you don’t feed your fish enough or if you feed them wrong.
Stress can happen if you feed your fish too little or too much. Make sure other fish don’t eat their food.
6. Lack of dissolved oxygen
Oxygen levels in water are extremely important. Fish can get stressed out if they don’t have enough oxygen.
Make sure your pump works and that the water has oxygen. You’ll definitely notice a drop in oxygen level if your pump malfunctions.
7. Overstocked fish tank
Make sure your fish tank does not have too many fish. Stress happens if your fish don’t have enough space. Overcrowding can increase competition among species.
Make sure it has enough space.
8. Wrong introduction of fishes in the tank
The introduction of fish to community tanks should work. Fish introductions can stress your fish.
9. Too bright tank Lighting
Fish don’t like bright light. Make sure you don’t light up your fish tank too brightly. Dark lights won’t do your fish any good.
How to identify that your fish is under stress?
We’ve seen the reasons why your fish can be stressed. We need to watch its behavior to figure that out.

Stressed fish have some specific symptoms. You have to watch them. They can be physical or behavioral. We’ll see some signs that will help us identify the fish.
1. Physical symptoms
- If your fish has white color spots on its body, it can be due to ich disease. This disease occurs due to stress. Stress can make your fish more prone to diseases like ich.
- If your brightly colored fish become paler, it can be due to stress. The chances of being under stress are pretty high in this case.
- Red streaking fins are another sign of stress in fish.
- Physical ailments such as sores, tattered fins, and other physical symptoms can happen due to stress. Stress can weaken the fish, making it easy prey for bacteria and parasites. These parasites are present in water.
2. Behavioral symptoms.
- If your fish is hiding in the tank or pressed against the wall inside the tank, it can be due to stress.
- Erratic swimming patterns, sprints, and darting inside the tank can be stressful. Fish can also crash against the tank wall in desperation.
- If your previously active fish is not so engaged or moving very slowly, it can signify stress.
- Stressed fishes will often scrape against decoration and gravel.
- Loss of appetite can be due to stress.
- If you observe your fish gasping for air at the surface, it can be under stress due to the low oxygen.
How to calm down stressed fish
Through multiple ways, we calm down our stressed fish. We will have a look at them.
1. Right tank mates
Always select the best tank mates for your fish. Don’t house big fish with small fish. Make sure that fishes don’t dominate each other.
2. Right tank size
Big water tanks always help you in case of fish stress. Always follow the general rule of thumb while selecting the right tank size. The fish tank should have one gallon of water for every inch of fish.
If you want to provide the best conditions, you can go for two gallons of water for every inch of fish.
3. Correct feeding
Ensure your fish with the right amount of food with proper nutrition. Keep them well-fed.
4. Add natural barrier
Just like us, fishes also need their private space. Provide them with enough natural barriers with holes so that they can stay there when needed.
5. Temperature
Water temperature should be in the optimal range without any fluctuations. The temperature should be set according to fish species. Use a heater to heat water if needed.
You can also invest in a good thermostat.
6. pH level
Water pH level should be in the correct range without any fluctuation. Each species can handle different pH levels. So make sure that you know the optimal pH range for your fish.
7. Weekly water change
Weekly water change can keep the water clean. It can help you to reduce fish stress.
8. A good aquarium filter
Your aquarium filter should be good. It should quickly filter out mechanical, chemical, and biological waste. So invest in a good aquarium filter.
9. The correct introduction of new fishes
Fish need to be correctly acclimatized before introducing into the tank. Follow the proper procedure to prevent stress.
Does water change affect fish?
Water change does not stress out fish. Make sure that you only change 30% water each week no more than that.
Before adding new water, make sure that it has the right temperature, ph level and is chlorine-free.
If you remove more than 30% water, then there is a good chance that it will also remove good bacteria. That bacteria keeps the chlorine level in water in limits.
How long can fish stress last?
That is impossible to say for sure. You should see changes in a few days if you fix your mistakes. It’s likely that your fish will die if you don’t see any changes.
Find the underlying cause as soon as you can and fix it. If you don’t, your fish won’t survive. Try to keep an eye on your fish to prevent any stress.
And always remember that precaution is better than cure.
Conclusion.
We’ve seen all the underlying causes of stress in your fish. And stress kills fish just like any other organism.
You should try to follow all the listed precautions in the article. Try to avoid any stress in your fish at all. Always try to keep your tank clean and fish well nourished. Don’t bring any new big fish to the tank that can scare other fish.
I hope you like the information provided here. Keep your fish healthy and safe.
Brian wasn’t just another Civil Engineer. His passion for Aquarium life was unknown to many until he decided to showcase it for the world. It seems like he made the right decision after all!