How To Clean Fish Tank After Betta Dies?

Being a betta fish keeper, nothing could be as disheartening as finding your betta fish dead in the tank, right? That’s what happens with all betta keepers. Dropsy, age, illness, water condition, or stress may cause death to your favorite betta.

Now you need to clean the fish tank before getting more fish. But, do you know how to clean a fish tank after betta dies?

No worries! I got your back! Though cleaning the fish tank is quite a daunting task, you can clean your fish tank by following a proper procedure. First, you need to remove the dead betta from the aquarium. Second, check the filtration system, and change the tank water. Finally, you can sterilize the fish tank. 

What happens if betta dies in the tank? What to do after the fish dies? If betta fish dies in the tank, should you change the water? How to sterilize a fish aquarium after betta fish dies?

Look no further than reading the entire article if you would like the answer to these questions.

9 betta pic collage
Owner: Acunk Van Holsten

What To Do After Betta Fish Dies?

Suppose you find your betta fish dead in the aquarium. Now, spot the dead betta and remove it from the tank as early as possible. Then find out what causes death to it. Check up the betta if it died because of age, illness, being stressed, injuries, dropsy, overfeeding, cold water, or an improper diet.

Once you know the reason, you can take proper measurements accordingly to control more betta death. If the betta dies of diseases, you will require disinfecting the fish tank before another betta adds to the list. In the latter part of the article, I’ll reveal the procedure of how to disinfect a betta fish tank after the betta dies.

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Do You Need To Clean Your Tank After A Betta Fish Dies?

You should clean the fish tank straightway once you see betta die in the tank. Otherwise, other bettas can get stressed in the aquarium. Before that, remove the dead betta from the aquarium before it gets rotten.

Dead betta in the fish tank can contaminate the water and reproduce bacteria and diseases to spread in the entire water tank to infect the healthy bettas. So you should clean the betta fish tank with proper sterilization to ensure other bettas’ safety in the aquarium.

How To Clean A Fish Tank After Betta Dies?

Betta fish death is common. But after the betta dies, the real challenge starts from there. Betta gets rotten after dying and causes water pollution in the betta tank to reproduce diseases. Consequently, other bettas may be affected. So you need to clean your fish tank.

Cleaning a fish tank is a pretty complicated process. But if you know the right process, cleaning a fish tank can be an absolute breeze. Below, I am going to give you a detailed step-by-step guide to make your job a cinch.

how do you know if a betta fish is going to die infographic. Shows most common signs before betta fish die including lethargy, less swimming, fading colors, loss of appetite, etc.

Want to get a printable version of this infographic? Click here! [If you want to use this infographic on your website, please link back to this post as the source!]

10 Steps To Clean A Fish Tank After Betta Dies

As a process of disinfecting the fish tank, cleaning the fish tank is mandatory after the betta fish dies. The following 10 steps will explain the whole procedure of cleaning the betta fish tank. Let’s dive into it!

Step 1: Spot The Corpse And Remove It From The Fish Tank:

Not all bettas can make it to float on the surface after they die. Dead bettas can be stuck under rocks and may get rotten if you cannot spot them. It always happens if you have a large fish tank with plenty of decorations. So spotting the dead bettas to remove them from the aquarium is the first task.

Step 2: Remove All Items:

After spotting and removing the betta corpse, you need to remove all items inside the fish tank, including rocks, alive bettas, and other substances. Keep the items in a safe place until the tank is ready to set everything as it is.

Step 3: Tear Down The Fish Tank

Now, take off all decorations of the fish tank. This would help you concentrate on each part of the tank and you can reach every place of the tank to clean them.

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Step 4: Clean The Fish Tank With Water

Now you can clean the fish tank with water and bleach solution. Wash off the parts of the tank properly. If there is any germ or bacteria in the tank, the bleach solution will take care of it. And you can apply the vinegar solution to clean the fish tank.

Step 5: Leave The Tank Dry

After cleaning the fish tank, wipe the tank with a towel and leave the tank for a while to get sunlight and it will dry the bleach solution.

Step 6: Check On The Filtration System And Change The Old Filter

Check out the filtration system if it works well. A strong filter can clean the contaminated water caused by the corpse. If the filter isn’t up to mark, change the old filter. The new filter will ensure a good filtration system.

close up of betta fish
Owner: Emily Brown

Step 7: Test The Water

Every time betta dies, it requires testing the quality of the water in the aquarium. Bettas may die for many reasons. But the dead betta can spread more diseases in the water. So making sure an ideal water standard in the fish tank is important.

Step 8: Cycle The Tank

Cycled tanks work like a biological filter that helps grow good bacteria. The wee and poo of bettas contain harmful ammonia. But a cycled tank can turn the wastes produced by dead betta into non-toxic nitrites.

Step 9: Change The Water

Changing water right after the death of the betta can be harmful. If you want to change the water massively, let the water parameter match with the tank’s water and wait 2 to 3 weeks until cycling the tank. Changing water can lower the amount of ammonia. Then you can leave new bettas in the tank. Make sure the water temperature is around 90 degrees Fahrenheit.

Step 10: Run The Betta Fish Tank Without Fish

Without fish, you can run the tank for two to three weeks and then experiment if there is any existence of ammonia that is caused by the dead fish. The absence of the fish for a few weeks can empty the parasites in the tank. Finally, test the water to check if it is back to normal for keeping bettas.

How To Sterilize The Betta Tank After A Fish Dies?

Once you are done cleaning the fish tank, you can sterilize your fish tank. There are some steps to sterilize the aquarium after the betta fish die. Besides these steps, there are two methods as well to sterilize your fish tank.

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Method-1: Vinegar Solution

When a betta dies, it leaves an indication that the remaining bettas’ life is also at stake. So Using vinegar solution, you can clean your fish tank to keep the other bettas safe and sound. Let’s take a look at the process of vinegar solution.

  • Apply a 1:1 range of vinegar solutions to the tank items.
  • Soak all fish tank items in vinegar solution for hours.
  • Once the items are soaked well, rinse them off properly.
  • Now you are all set to use the tank and equipment to keep your bettas into it.
  • Fill in the tank with water now.
  • Use a good quality water conditioner.
  • If you need a strong solution, apply a 2:1 range vinegar solution.

Method-2: Bleach Solution

Bleach is a super cleaning solution for your fish aquarium as well. You can apply bleach if betta dies in the aquarium. Follow the procedures below to use the bleach solution in the aquarium:

  • Pour the bleach into a spray bottle – One part bleach with 8 parts water.
  • Spray the fish tank.
  • Now leave it for ten to fifteen minutes to sit.
  • Don’t leave it for longer as bleach is corrosive to damages your fish tank.
  • Use air dry for twenty-four hours before using the tank to do away with the residue left in the tank.
  • Finally, the tank is all set to use.

What Happens If Your Betta Fish Dies?

Betta fish exposes some traits when it dies in the fish tank. Even after the death, oxygen exists in betta’s body. But betta tissues break down slowly and betta’s belly gets full of gas.

As the gas can’t emit from the betta’s belly, the betta looks like a fish balloon. Meanwhile, the betta balloon is lighter than the water and so dead fish floats on the surface of the water. However, not always dead bettas float on the water.

Wrap Up:

I hope by now you are well aware of how to clean fish tank after betta dies. You should remove the dead betta and sterilize the fish tank. With the proper actions and steps, you can easily prepare your fish tank for new fish after a betta dies.

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Muntaseer Rahman

About Author

Hello, I’m Muntaseer Rahman, the owner of I’m passionate about aquarium pets like shrimps, snails, crabs, and crayfish. I’ve created this website to share my expertise and help you provide better care for these amazing pets.


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