How To Clean a Betta Fish Tank in 6 Easy Steps

Learning how to clean your betta fish tank is crucial to basic fish care.

For new betta owners, cleaning their aquarium may seem difficult.

But cleaning a betta fish tank is not as hard as you might think.

You only need a few simple supplies and a little time set aside for tank cleaning.

Our helpful step-by-step guide provides detailed information about how to clean your betta fish tank in six easy steps.

We also discuss why maintaining a clean environment is essential for your betta.

how to clean a betta fish tank atf

Why Cleaning Your Betta Tank Is So Important

Nobody likes living in a dirty house, and neither does your betta.

A dirty tank is not only uncomfortable for your betta, but it can make your fish sick.

The most common cause of many betta fish diseases is an unclean tank and poor water parameters.

Despite their small size, bettas produce a lot of fish waste. If your betta has tank mates, fish waste accumulates very fast.

As fish waste breaks down, it creates harmful bacteria and dangerous ammonia levels. Uneaten food and decaying plants add even more bacteria and toxins.

A concentration of ammonia above 0 ppm (parts per million) causes painful burns and can kill your betta.

Establishing a regular cleaning routine prevents dangerous bacteria and toxins from building up in your aquarium water.

Maintaining a clean tank environment ensures you have a healthy and happy betta.

Step-by-Step Guide to Cleaning a Betta Fish Tank

cleaning betta tank steps

1. Prepare for Cleaning

Before you start cleaning your betta fish tank, you must do a few things.

Always wash your hands before handling anything in your betta’s tank. Ensure you rinse away all of the soap.

I recommend wearing disposable gloves if you have small cuts on your hands. Gloves protect your betta tank from contamination and prevent you from getting a bacterial infection.

Removing your betta while you clean the tank is unnecessary. Taking your betta out of the tank causes a lot of stress for your fish.

Only remove your betta from the tank for medical treatments. Placing your betta in a quarantine tank avoids contaminating the main tank with medications.

Quarantining also prevents the spreading of contagious diseases to your betta’s tank mates.

Gather the supplies you need before getting started. This saves time and ensures you have everything you need for a proper tank cleaning.

Since your heater is off while cleaning the tank, you don’t want the water temperature fluctuating too much.

Don’t do a rush job of cleaning your tank. But don’t take too much time, either.

We listed the supplies you need below.


  • Gravel vacuum or siphon
  • 2 large buckets
  • Water conditioner
  • Algae scraper
  • Thermometer
  • Clean cloth or sponge
  • Filter media (if applicable)

2. Remove the Algae

Using your algae scraper, remove excess algae buildup from the sides of your tank.

A magnetic algae scraper makes this job easy. It also prevents you from putting your hands in the tank water and disturbing your betta.

Take care when using a razor blade for algae removal. Use slow movements so you do not injure yourself or scratch your tank.

Always use a plastic razor if you have an acrylic tank. Acrylic is more prone to scratches than glass.

Tips for Algae Control

There are a few methods of preventing excess algae buildup between tank cleanings.

Consider getting algae eaters for your betta tank. These aquatic animals feed on algae and keep your tank clean.

Some good choices for algae eaters include:

  • Mystery snails
  • Amano shrimp
  • Plecostomus
  • Otocinclus

If your algae eaters remove all of the algae from your tank, you must supplement their diet with algae wafers.

The type of lighting you use in your betta tank also affects algae growth.

Bright lights and sunlight increase algae growth in your betta tank.

Unless you have plants with strong lighting needs, keep your lights low or moderate.

Avoid placing your tank near a window with direct sunlight. Not only does sunlight encourage algae growth, but it also causes water temperature fluctuations.

3. Clean the Substrate and Remove Some Water

betta subtrate cleaning

Now, it is time to clean your substrate and start a water change.

Turn off your filter, heater, and lights before you begin. This prevents the chance of an electric shock.

Lower water levels can also burn out your heater if it does not have an automatic shut-off feature.

Using your gravel vacuum, clean your substrate as it siphons the dirty water into one of your buckets.

Keep an eye on where your betta is so you do not harm your fish by accident.

Be sure you remove all of the food waste and other debris from your substrate. Even small bits of waste left behind can cause issues with your water parameters.

Take care not to remove more than 25% of your tank water. Removing too much water crashes your nitrogen cycle and creates unstable water parameters.

You may use the dirty tank water for watering houseplants. But save some of it for rinsing your filter.

How Often Should You Perform a Partial Water Change?

Partial water changes remove harmful toxins and replenish the minerals and nutrients in your aquarium water.

A 5-gallon tank needs a 10-20% water change once per week. Never place your betta in a tank smaller than 5 gallons.

Small fish bowls and vases do not make a good home for a betta. They also suffer from constant poor water conditions due to the lack of a nitrogen cycle.

The nitrogen cycle can only take place in tanks with at least a 5-gallon volume. Beneficial bacteria in the nitrogen cycle convert dangerous ammonia into less harmful nitrates.

These beneficial bacteria keep your tank parameters more stable between water changes.

Larger tanks usually need less frequent water changes. A 20-gallon tank may only need a biweekly water change of 20-25%.

The time between water changes for larger tanks depends on the results from your aquarium testing kit. Consider weekly partial water changes if your tank tests outside of the optimal range.

4. Clean the Decorations

Your decorations don’t need cleaning every time you do a water change.

But when your tank decorations start collecting algae, they need a good scrub.

Remove the decorations from your betta tank and wash them in warm or boiling water.

A toothbrush is a useful tool for scrubbing the grime out of the nooks and crannies of your decorations.

If your betta gets sick with a bacterial infection, you must sanitize the objects in the tank.

You may use a solution of 95% water to 5% bleach for sanitizing tank decorations.

Give the decorations a good rinse and let them air-dry before placing them back in the tank.

As long as your tank decorations are not covered in grime or algae, you may skip this step.

5. Clean the Filter

Check your filter media for any clogs. Clogged filter media reduces the efficiency of your filtration system.

If your filter has cartridge media, check if it needs replacing.

Never clean your filter sponges or other biological media in fresh water. Doing this removes beneficial bacteria colonies and disrupts your tank’s nitrogen cycle.

Instead, rinse your biological media in some of the dirty tank water you removed from the tank.

Be gentle when rinsing so you do not disturb the beneficial bacteria too much.

Put your filter media back in your filter when you finish cleaning it.

This is another step you don’t always need with every water change.

6. Add Clean Water Back to the Tank

water conditioner for betta tank cleaning

The last step is refilling your tank.

Add as much water as you removed earlier to the clean bucket.

Most betta fish owners use warm tap water to fill their tanks. If you use tap water, you must add a water conditioner.

A water conditioner neutralizes the chlorine and chloramine found in tap water. Chlorine and chloramine are very toxic to betta fish.

Exposure to these chemicals causes severe burns and can kill your betta.

Follow the dosage instructions on the bottle of water conditioner.

After adding the water conditioner, stir the water so the solution mixes.

Wait a few minutes so the water conditioner can neutralize the chlorine and chloramine.

Before adding the clean water back to the tank, you must ensure it is at the right temperature.

If the temperature of the clean water is different from the tank temperature, it causes sudden changes.

Temperature fluctuations can cause stress in your betta.

After ensuring the fresh water is at the right temperature, pour it into your betta tank. Pouring the water over a small bowl or plate prevents disturbances to the substrate and tank decor.

Once you refill the tank, turn your heater and filter back on.

Since cleaning the tank is a bit stressful for your betta, leave the lights off for a little while. This gives your betta some time to calm down and avoids causing extra stress.

Use a clean cloth or sponge for wiping up any spills or for spot-cleaning the outside of your betta tank.

What To Use When Cleaning a New Tank

When setting up your betta tank for the first time, you must clean the tank and decorations before putting it all together and adding water.

I also recommend soaking your gravel substrate in warm water for a couple of hours. This removes any dust particles created during the shipping process.

If you use a sand substrate, you must soak it as well. Soaking the sand prevents it from creating a cloudy tank when you add water.

Never use soap when cleaning your tank or decorations. Even small amounts of soap residue can kill your betta fish.

Instead, you may use a 1:1 ratio of water and white vinegar.

Rinse your tank and decorations very well after cleaning. Leftover vinegar residue can affect your tank’s pH levels.

For complete safety, warm water is effective for rinsing a new tank and decorations.

Dry the wet surfaces with a clean cloth. This removes any traces of tap water.

Reasons Why a Betta Tank Gets Dirty

betta tank dirty mistakes

There are several reasons why your tank seems dirtier than usual between cleanings.

Fixing the underlying cause can help you maintain cleaner tank conditions for your betta.

Below are the most common causes of a dirty betta fish tank.


The size of a betta’s stomach is around the same size as its eyes.

A common mistake among beginners is dumping a bunch of pellets in their betta tank at feeding time.

This causes bloating and other digestive issues for your betta. An excess of food means extra fish waste, as well.

The leftover food also creates poor water conditions.

As the food waste decays, it releases harmful bacteria and ammonia. This can cause dangerous ammonia spikes and make your tank water cloudy.

Betta fish only need 2-4 pellets at each feeding. You may feed your betta this amount twice daily, at least 6-8 hours apart.

Poor Maintenance

It goes without saying, but if you don’t clean your tank regularly, you end up with poor water conditions.

Without regular water changes, bacteria, toxins, and algae accumulate. This gives your tank a cloudy appearance and creates an unhealthy environment for your betta.

Cloudy water can clear up with regular water changes. But removing an algae outbreak is more of a challenge.

Establish a regular tank cleaning routine and stick with it.

Routine cleaning makes your tank look better and creates a healthier environment for your betta.

Poor Water Source

Tap water may contain heavy metals or other unknown substances. If you suspect your tap water is the cause of your dirty tank, have your water tested.

Most water conditioners remove certain metals and toxins. Carbon filter media can help purify your water, as well.

Live aquarium plants also help filter out heavy metals and other toxins.

According to the USDA, Duckweed is very effective in the removal of heavy metals and toxins.

You may consider using reverse osmosis or distilled water in your betta tank. These types of water work fine if you do not have access to a safe municipal water source.

But these types of water lack essential nutrients and minerals your betta needs. You must remineralize these types of water before using them in your betta tank.

Final Thoughts on Cleaning a Betta Fish Tank

Your betta appreciates a clean home as much as you do.

A dirty tank can accumulate toxins and excess algae in a short amount of time. This creates a very dangerous environment for your betta.

Maintaining a clean tank is vital for your betta’s health and happiness. Establish a weekly cleaning routine, and don’t stray from it.

How useful was this post?

Click on a star to rate it!

As you found this post useful...

Follow us on social media!

We are sorry that this post was not useful for you!

Let us improve this post!

Tell us how we can improve this post?


Toni Tedescucci is a freelance writer who loves all animals, especially betta fish. When she isn’t busy writing for Betta Fish Bay, she’s spending time with her family or getting cozy with her cats and a good book.

Follow Us on Facebook!

Get betta fish fun facts right on your Facebook feed and see when we share new content by following our page on Facebook.

blue betta fish

Advertiser Disclosure

We are reader-supported and may earn an affiliate commission when you buy through links on our website. To be 100% clear, you should assume that we will earn a commission on any product you purchase after clicking on links or images on this website.

Our affiliate partners include but are not limited to

In addition, we generate revenue through advertisements within the body of the articles you read on our site.

Although we only recommend products that we feel are of the best quality (which we may or may not have personal experience with) and represent value for money, you should be aware that our opinions can differ.

A product we like and recommend may not be suitable for your unique goals. So always be sure to do your due diligence on any product before you purchase it.