Fish Dying After Water Change: Why & How To Save

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Improper water changes still remain among the most common causes of aquarium fish deaths. This is a prevalent problem among many beginner hobbyists, but even experienced aquarists lose one or two fish to small errors during the water-changing process.

Many things can go wrong to make your fish die immediately after a water change. Preventative measures like sticking to proper water change procedures remain the best solution to keeping your fish alive. But a few quick actions can also be taken to help save your fish once you notice the dying symptoms.

fish dying after water change

A few of the steps you can take to save a dying fish after a water change is to ensure you stop feeding the fish immediately and also increase the oxygen content in the water.

Aquarium salt has also been known to be a lifesaver in such situations. Do not forget to make use of chemical removers and detoxifiers if you know poor water parameters are the cause.

Read on to learn of the in-depth procedures that can save your fish’s life in a matter of minutes. Get to learn how to prevent your fish from dying when you change the water and what principles you should stick to during this process.

Why Fish Die After Water Change?

Fish die after a water change due to sudden water shock. All aquarium fish can adjust to gradual shifts in their surroundings, but any sudden shifts from their previous environment will shock the fish, alter its internal process and stress it severely, leading to death.

The fish might die immediately or shortly after; however, it is always advisable to keep an eye on any signs of stress to make sure water changes do not affect your aquarium.

Water changes are beneficial in maintaining a healthy environment for your fish to call home. The change helps remove nitrates and maintain the pH levels that are always falling. It cleans any mess that is in the tank and provides a good opportunity to make any changes to the setup you have.

Water changes also help in getting rid of leftover food, which accumulates all over the tank. Changes are also vital in ensuring there isn’t any mineral buildup that can cause a chain reaction in chemical compositions.

If having clear water that isn’t blurry is important to you, then you are very likely going to perform frequent water changes, particularly with bigger fish that produce more waste and eat more.

Regardless of the benefits, water changes pose a great threat to your fish. This is because several things can go wrong during the process, leading to unforeseen consequences such as the death of your fish.

It is harder to pinpoint the problems, especially if the issue does not lie in improper water parameters such as pH, ammonia, or temperature. Therefore, it is important to focus more on preventive measures so as to ensure your fish never have to suffer after water changes. You do this by sticking to the proper water change procedures.

Prevention is the most important step because it is almost impossible to save a fish once you start noticing signs of impending death. The symptoms in this scenario might include the fish gasping for air, laying at the bottom of the tank, acting abnormally and in a stressed manner, or swimming frantically.

If you end up following the right procedures or happen to make a tiny error during the process, then paying attention to the signs of a dying fish will become vital. Urgently act when you notice the symptoms.

6 Simple Steps to Save Dying Fish After Water Change

Save Dying Fish After Water Change

Please note that you need to be quick and precise about these next actions; time is of the essence. It is a good policy to always start by checking the water parameters since these are the biggest causes of the problem.

You also want to pay attention to the way the fish is acting. For example, a fish at the top gasping for air indicates there isn’t enough oxygen in the water. These signs and changes in behavior will help you know the best way to save your fish.

Below are the main signs of a dying fish after water change:

  • The fish is swimming at top of tank after water change
  • The fish is hyperactive & swimming erratically after water change
  • If the fish swims in a disoriented manner
  • The fish is swimming upside down after the water change
  • It is laying at bottom of tank after water change
  • The fish huddled in corner of tank after the water change
  • It has bulging eyes and you can see clear signs of breathing struggles
  • The fish is bloated
  • The fish loses color
  • Lots of uneaten food in the tank

Once you take note of the signs, proceed to follow the following steps to save the fish:

1. Do Not Feed The Fish

If the fish is dying, then you are most likely going to have lots of uneaten food in the tank. Stop feeding the fish and remove any leftover foods from the tank.

The digestive system of a dying fish is not going to be working optimally during this stressful period. It is important to avoid putting more stress on the fish that is already struggling. Removing uneaten food and not feeding the fish will also help prevent bloating, which can make it harder to save the fish.

2. Check the Water Parameters

Take steps back and notice what you would have done to affect the water parameters. Simple things around the house, like opening another tap or shower, can cause the water parameters in your tank to change.

Take note of anything you may have forgotten to add. Maybe you did not add a water conditioner to the tank. Did any chemicals accidentally enter the tank from the outside? Or did you perform the water change too quickly and remove lots of healthy bacteria.

Use a simple water testing kit for this since time is of the essence. Check the temperature, the pH levels, water quality, and also look at how the fish is behaving.

If they are rolling over, then the condition is severe, probably caused by a severe shock from a high pH change. In many cases, water temperature and chemical imbalances are going to be the main culprits that are affecting your fish’s health.

Once you can pin point what water parameters need your attention, then you may proceed to apply the solutions.

3. Reduce the Water Temperatures

Fish are cold-blooded animals which means that they cannot control their body heat from within themselves. They rely on the environment’s temperature to regulate their normal body functions.

Small temperature changes are not detrimental to the fish’s health so long as it is done gradually. However, in cases of fast temperature changes, the fish are sent into sudden thermal shock, and this will be followed later on with the loss of color intensity.

High temperatures not only change the fish’s color but also damages the fish’s immune system which means you will be dealing with several long-term consequences.

Reduce the water temperature to the recommended setting, perfect for your specific species. You will have to keep an eye on the fish from now on for any health issues but you will be able to save its life.

4. Increase The Oxygen Content In The Water

High temperatures also mean that oxygen is not going to be easily dissolved in the water. This causes oxygen deprivation and you will notice the fish swimming at the top of the tank, gasping for air, and struggling to breathe in a variety of ways.

The fish may also be swimming erratically, have bulging eyes, and suddenly become hyperactive. These are symptoms of stress and the quickest solution is to aerate the water.

Add an airstone into the tank to increase the amount of air in the tank. You can also agitate the water using your filter to ensure more oxygen is dissolved into the tank to counter the imbalance.

Agitating the water surfaces also solves another problem: water that has too much saturated gas. If the water contains too much gas then bubbles will form all over the fish’s externals and internals, threatening its life. This is because the gases are escaping the water to balance out the pressure difference between outside air and the water.

Keep an eye on the fish’s behavior to see if the solutions are helping. If the cause is low oxygen levels (which also means ammonia is too high), then the aeration will return your fish to their normal behaviors and you would have saved a life.

Proceed with other solutions if the aeration does not work.

5. Use Water Conditioners, Chemical Removers, Dechlorinators, And Detoxifiers

Water quality is compromised when you have any form of chemical imbalance in the tank. This is where water conditioners come in handy; they help even out any outside chemicals that may enter the system through chemical filtration. Every water change should include water conditioners.

Dechloronators are important in saving the fish’s life when you notice that you used tap water to perform the water change. Tap water has lots of chlorine and chloramines which can easily and quickly kill your fish. Dechloronators help counter the imbalance and can also help remove heavy metals and ammonia from the water.

pH level changes are toxic to the fish. If the environment is too acidic then the fish may suffer from skin burns, have trouble breathing, you will notice some eye damage, and they will bloat with thick skin and gills. If it is too alkaline then fish will suffer from cellular membrane destruction.

Ensure you test the pH levels before any water change. If the pH levels are still improper after the change then adding driftwood, dolomite, crushed coral gravel, peat moss, or pellets to the tank can help counter the effects, but please note that damages caused by bad pH levels are severe.

Use an ammonia neutralizer in cases where your test kit shows you have more ammonia than is required.

Use chemical removers to get rid of high nitrate levels. Nitrates get too high if you haven’t performed a water change in a long time.

Your fish end up getting used to the high nitrate levels and once you perform a water change, the sudden osmotic pressure change between the waters sends the fish into osmotic shock. Chemical removers will ensure your nitrate levels are balanced to stop the fish from getting shocked.

Related: Can Betta Fish Live in Tap Water?

6. Use Aquarium Salt

If you have performed all the water tests and countered all the chemical imbalances you could think of, then it is time to give aquarium salt a chance.

Aquarium salt can be beneficial in dealing with fish diseases and lowering stresses in fish. It is a solution that should be used sparingly since too much of it can cause the opposite effect.

The best solution for saving a dying fish after water change depends on the cause of the problem. It is important to learn how to quickly diagnose the causes of death and act hastily.

Causes of A Fish Dying After Water Change

Now that you know how to save your fish, it is time to look at what caused the problem so as to prevent it from ever happening in the future.

It is important to note that all causes have to do with improper water change procedures or mistakes made during the process. There are other unrelated causes, like sickly fish or old-age fish, but all of those causes are amplified by the errors made during the water change.

  • Improper Water Parameters, including pH and temperature
  • External Chemical Poisoning
  • Chlorine Poisoning
  • High nitrate and Ammonia levels
  • Lack of beneficial bacteria – vacuumed substrate
  • Osmotic Shock
  • Highly gas-saturated water is characterized by bubbles forming inside the fish
  • Unrelated Causes like infections and old age

Tips and Tricks on How to Perform Proper Water Change

Prevention is better than cure.

  • Stick to recommended water change percentages

A 25% water change is always best; this is if you perform regular water changes, there are a few cases where you may be warranted to perform a full water change (like when your fishes are plagued by an infection).

Refill the tank slowly. A small water change ensures the fish have time to adjust to new water parameters and conditions.

You should also not overclean the tank since this will get rid of healthy bacteria, which causes ammonia spikes.

  • Clean the filters but do not completely dry them

This helps keep healthy bacteria in and ensure it is not clogged to maintain high clean water quality

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How Can You Save a Dying Fish Quickly?

The quickest way to save a dying fish is to check for the water quality and water parameters. These are the number one causes of fish death and knowing the water quality imbalance in your tank setup will pin point the cause and let you know of what needs to be remedied.

Why Is My Fish Dying Even After Water Change?

Performing water changes is one of the best ways to address a rising death rate in your tank. However, it is not a full-proof solution that will prevent your fish from ever dying. If the water changes do not help keep your fish alive then it is best to look for the root cause of death.

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