Effective way to sanitize fish tank

Effective Sanitization of Your Fish Tank After Disease


If you are a fish keeper and growing fishes for a longer period of time, then you will have come to a sad and worst situation. This happens when a beloved fish in your aquarium dies either naturally or by some disease. But How to clean a fish tank after it dies? First, remove the dead fish from the tank and keep it aside from other fishes. Perform small inspections over the reason for death. If the fish died naturally, then complete cleaning is not necessary. If the death is due to any infections, a complete cleaning along with few other precautions is highly necessary. Most times, Fishes may die inside the tank due to natural diseases. It may also happen due to chemicals and other toxins inside the tank. Diseases are one of the most threatening things for a fish group inside a tank. It affects many fishes at a time and may even cause fatality. So it is highly necessary to keep the tanks clean and healthy. But if you come across a tragic scene of you’re beautiful fish not alive anymore, but still want to clean and sterilize the tank for the health of other fishes then read on the blog. We know it is tragic to lose a beautiful cute little fish. But that is how life works. Get over the past fear ones and look up for the well-being of present ones. In this blog, we will explain what to do when a fish dies in your tank and how to clean and sterilize it. We will also cover some disease prevention tips for fishes in an aquarium. So, Sit Back, Stay Strong and Give a complete read.

Why Fish Get Sick In An Aquarium

Why fish gets sick in aquarium
Like humans, fish get sick. There are various factors that affect the health of fishes and cause disease. But, we can compile them into three major factors. The three major factors that cause disease in an aquarium are 

  • Some Fish in the Tank.
  • Disease-causing pathogens.
  • Stress factors.
  1. Some fishes in the tank may already be diseased by coming in contact with pathogens. This may either be due to poor feeding habits or unclean water conditions. These fishes when coming in contact with other healthier fishes, will cause and spread disease among the school.
  2. Disease-causing pathogens are the major reasons for disease spread. Just like some bacteria and viruses are pathogenic to humans, Fishes fall sick when coming in contact with certain pathogens.
  3. Stress factors are mainly improper tank conditions like Improper tank Temperature, Water pH, Over Crowing of fishes, and some toxic chemicals in tank water.

Fishes fall sick when they come in either of two conditions. In normal tank conditions, fishes can fight off bacteria and viruses. But, when the tank conditions are difficult to handle, fishes become more stressed. This in addition to contact with pathogens will cause them to fall so much easier. Pathogens mainly enter or develop inside the tank when the water is not changed frequently and the tank is not cleaned properly. So, it is highly important to maintain a clean tank and change tank water frequently from time to time. It is also necessary to know what tank conditions your fish require. Tropical fishes love to be in warmer water compared to other fishes. But when they are kept in colder conditions, it will cause them to go under stress. They tend to spend more energy on temperature rather than on pathogen defense. Similar is the case for all tank conditions like pH, Temperature, Water Flow, and even school crowding depending on the size of the tank. If you maintain the optimum condition required by your fish inside the tank, feed them high-quality food, and perform regular maintenance, you can easily prevent fishes from getting diseased. Now knowing about fish diseases and how to maintain them, let us move on to how to clean a fish tank after disease.B

How To Clean Fish Tanks After Disease?

Diseases are common in both man and fishes. It is better to prevent than cure. But how to clean your freshwater tank when any of your fish is affected or dead? Let us get to know about it step by step. To know more about fish tank cleaning visit How to clean your fish tank.

Step 1: Clear Fishes From The Tank

It is important to remove and isolate the healthy fishes from the diseased ones. This will prevent the disease from spreading among the unaffected fishes. Once removed, move them to a temporary tank. This is called a quarantining tank and this process is called Quarantining the fish. Once done, let us move to remove the materials inside the tank.

Step 2: Remove Gravel, Plants And Decorations From Aquarium

Now, remove everything inside the tank. This will include all decorations, rocks, pebbles, live Plants, Organic items, Driftwood, and any removable material Then we can remove the Heater, Filter, and Aquarium light connected to the aquarium. They are electronic machines so make sure to handle them with care while removing them. Now, we are left with the Substrate. The substrate is the most polluted material inside a tank. So, it must be taken more care of. When it is of normal condition, we would just consider vacuuming the Substrate and reusing it again. With fishes dying of diseases, the substrate will sure contain unwanted bacteria. So, it is better to discard them and put them up with new substrate inside the tank. You may get some advice from fish keepers to clean the substrate with a cleansing agent. But Cleaning substrate with a cleansing agent will not remove the bacteria. This will still cause disease after cleansing. So, better replace and get a new substrate. Your fish will thank you later.

Step 3: Scrub With Cleansing Solution

Now mix a solution of bleach in 1 to 19 ratios with water. With the help of a scrubbing pad, scrub the whole area of the tank thoroughly. Apply the bleach solution completely spotless on the tank surface. Always use a brand new scrubber to clean your fish tank. Never use a scrubber that is used for other cleaning purposes. You may also use some razor or blade-like tools to clean patches that are tough to remove with sponge scrubbers. Bleach is a very powerful cleaning agent and it will surely kill every harmful bacteria inside the tank. Now, clean the bleach with water. But, make sure to wash the tank thoroughly to remove bleach from the tank. If not removed properly, Bleach will cause huge stress and even disease again to your fishes.

Step 4: Clean Your Tank Filter

Now, clean the tank filter with the same bleach solution to remove bacteria. Filters are the ones pumping water back inside the tank and circulation all through the tank. If the disease was bad, you can change for a new filter. Often it is better to change the equipment or clean them thoroughly before introduction. When not cleaned properly, the bacteria would still be present and will grow back again. Remove every part of the filter and clean it thoroughly with bleach. Then, clean it completely with water. The Filter after washing must be free of bacteria and bleach.

Step 5: Clean Decorations And Rocks

You must also clean up the decorative items to make them bacteria and algae-free. Over time, Algae and organic matter will start to grow over the decorations and rocks. Clean them by scrubbing them off with the scrubber. This will help remove the green particles and disease-causing microorganisms to die. Use a toothbrush to clean difficult areas. It is even easier to clean rocks and pebbles. Just give them a small scrub treatment and sink them in bleach solutions for 5-10 minutes. Later, Pick them back and clean them with normal water. You can also use hot water to remove strong stains.

Step 6: Cleaning External Lights and Plants

Just like the previous steps, lean the external fish tank lights with bleach solution. Remember! Always wash the bleach off completely. You can even wash it twice to remove bleach. Bleach is toxic to fishes and causes more damage to them inside the tank. The plants will get damaged when excessive bleach is used. So, use less or even no bleach while cleaning the plant and organic materials of your tank. Once done cleaning, let them dry for a while. Make sure the water doesn’t affect the electronic areas of your Heater, Filter, and Tank Light.

Step 7: Setup the Fishes inside Tank again

Now, set up the tank items again. You can always try on new locations for your plants and decorations. If you changed the substrate, you must go through a complete nitrogen cycle before transferring the fishes from quarantine to the tank. This happens for a few weeks. But, you can speed up the cycling process by adding some beneficial bacteria periodically inside the tank. And finally, you can add your healthy fishes back to the tank. Now, let us know some reasons on why your fish die in aquarium.

Top 6 Common Reasons Why Your Fish Dies

The main reason for the fishes to die inside the tank is Stress. Humans are more prone to disease if they are in stressed conditions. Similarly, fishes also become more prone to disease when stressed.

The major reasons that cause stress for fish in an aquarium are

  • Not setting up the tank properly.
  • Buying the wrong type of fish.
  • Buying fish without knowing the in-tank conditions.
  • Over-feeding your pet fish.
  • Overcrowding a smaller tank with many fish.
  • Mixing incompatible fishes in the same tank.

These are the major reasons that cause stress among fishes. So, always make a study on how your tank conditions are and buy fish accordingly. With that said, let us see how to prevent fish diseases in tank conditions.

Preventing Fish Disease In Tank

Prevention is better than cure. So it is always better to prevent fish diseases than to prevent them from occurring. Let us see some important points to follow to keep your fish healthy.

  • Always provide good quality food for feeding. Use chlorine-free water inside the tank.
  • Perform regular tank maintenance and cleaning for a healthy tank setup.
  • Quarantine fishes before transferring to another tank.
  • Before adding new tank mates, always quarantine for 5 to 7 days in a separate tank.
  • Perform 20% water change every week. Clean tank and tank filter at least twice a week.

If these points are followed carefully, you can easily avoid disease spread among your cute little pet fishes.

Final Words For Fish Keepers

As I said earlier “Prevention is better than cure”. So always try to prevent your beloved fishes from getting diseases rather than treating them. Also, take more care while cleaning the tank if fish dies due to bacterial or other parasitic diseases. After every fish passes away, make sure if it is natural or due to some stress. You can learn easily from experience, especially in the world of pet keeping. We hope this article helped you on fish diseases and cleaning your tank when your beloved fish dies. Comment below and tell us your experience about your pet fish loss and how you came over the tragedy. If you liked this post do share it with your friends and family. Cause sharing is caring. See ya! Until then, keep growing your aquarium

Commonly Asked Questions

1. How to Disinfect a Fish Tank after a Fish Dies?

Fishes die when bacteria affect them. Dead fish in a tank means the tank is filled with bad bacteria. It must be removed. The process of removing bacteria inside the tank is called disinfecting a tank. Now, clean the tank with bleach-water solution. The solution must be in the ratio of bleach to 19 water. Mildly, scrub the tank and tank materials with solution and wash thoroughly with water. Make sure to remove the bleach completely before introducing it into the tank. You can clean the plant materials with mild warm water. Fill the tank with chlorine free water. Once done cleaning, get the fishes back into the tank. Make sure to add the fishes after the Nitrogen Cycle, if the substrate is changed. 

2. Can You Bleach Fish Tanks? 

Yes bleach can be used to remove unwanted bacteria from the tank. 1 part bleach and 19 parts water solution can be used to rinse out your fish tank. Once done with bleaching, check for any bleach smell from the tank’s interior. If you smell bleach, wash again until the bleach is gone completely. Bleach is highly poisonous to fishes. So remove bleach completely before introducing the fishes inside the aquarium 

3. What’s the best way to get rid of the fish corpse? 

It is really sad when your fish dies. It is also really confusing where and how to dispose of the corpse. The best way to dispose of a dead fish corpse is to Bury It. Burying will cause no harm to the environment and is more respectful to bury your beloved pet fish. Never flush them in the toilet as it will get to your local water treatment line and contaminate the treatment plant. You may also burn or incinerate it. It will work but will leave behind a mask and some debris. Also, don’t try to toss them in the garbage bin. This will cause rotting and foul smell. 

4. How many deaths are deemed acceptable in a community tank? 

Lifespan of fishes vary on the variety and few other conditions. If your tank has a huge school, then losing a few fishes around the year will be natural due to aging. Smaller fishes live a short lifespan and larger fishes have longer life spans. If your tank is seeing more deaths in a smaller time period, then it is something to be taken care of. 

5. When can I restock with fish after any deaths? 

Restocking inside the tank must be done after complete treatment of the tank. If the death is of natural cause, then you can restock the fish within a week or 10 days. If the fishes died of some disease or toxic chemicals, then reattach your fishes slowly inside the tank. Add your most resistant fish first and then slowly add the sensitive ones inside the tank. But never add everything at once for Restocking after a tank treatment.

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