How To Clean A Betta Fish Tank

It’s a good idea to have a regular cleaning regimen for your betta tank. Sometimes waste products can build up in the gravel of aquariums.

Doing a full clean out will decrease the chance of the water quality suffering, and therefore reduce the likelihood of your betta getting sick.

Algae can also build up in the aquarium. It isn’t harmful but can be unsightly, so giving everything a quick scrub will keep things looking spick and span and ensure that you maintain a clean betta tank.

How often to clean your betta fish tank

How often you need to clean your betta tank does depend on a number of things: Does your aquarium have a filter? How big is your aquarium? Do you have more than just a betta in your aquarium?

If you have read any of our other articles on betta care, you’ll know that we really emphasise the importance of having a filter. Not only does it control the water quality, but it decreases time-consuming things like changing water or aquarium cleaning.

For a 19 litre betta aquarium with just a betta fish and a filter, you’ll only need to give it a full clean out every 6 to 8 months.

Some planted aquariums with a good filter and a balanced ecosystem of ‘clean up’ tank mates can go years without a clean.

If you are keeping your betta in a 19 litre aquarium without a filter, you’ll probably need to clean it every 4 to 5 weeks, as fish poop and waste products can really build up quickly in that amount of time.

Typically, though, and especially for beginners, we don't recommend keeping a betta without a filter.

How long does it take to clean a betta aquarium?

It depends how extensively you want to clean. If you have a betta aquarium with a bit a gravel, a few ornaments and a few fake plants, it won’t take too much time. The tanks recommended in our ‘best betta tanks’ article are easy to clean and won’t take too long.

A good time to clean your aquarium is when you’re doing a water change. This can be either a small, perhaps weekly, water change or a large bi-monthly water change. This means you can add some fresh water to the aquarium once it’s cleaned.

Read our page on water changes here.

How to do a thorough aquarium clean

  1. Start by preparing any water that you intend to use for a water change. If you’re going to be doing a large water change after cleaning (80% for example) you’ll need to prepare this in advance, making sure it’s the right water condition and temperature for your betta when it’s put back into the aquarium. You can read more about water preparation here.
  2. This brings us to our next step: removing the fish. Remove the betta from the aquarium using a net or cup. You can keep the little guy in a large mug (or something similar) with some water from the aquarium whilst you clean. Cover the temporary container so that your betta can’t jump out.
  3. Next (if replacing any water after cleaning) collect the percentage of aquarium water that will need to be added back to the aquarium and store it in a clean container. For example, if you’re doing an 80% water change, collect 20%, if you’re doing 20%, collect 80%, etc. If your aquarium has a filter, a good place to collect the water is from the filtration output nozzle. The remaining water can then be disposed of so that you can clean the aquarium.
  4. Next, remove any ornaments, rocks or artificial plants, etc. Scoop the gravel out with a small spade or use your hands and place it in a bucket. Once everything is removed from the aquarium, you can start to wash and scrub the aquarium. It’s okay to wash out the aquarium with tap water, but be sure to scrub the aquarium with something suitable, as some cloths and towels contain cleaning chemicals which can be harmful to the aquarium. It’s best to use an aquarium scrub or something like a natural sea sponge. You can spray the sides of the aquarium with a small hose or a tap tail. Once the inside looks clean, with no bits of waste or debris left, you can start cleaning the other stuff.
  5. To wash the gravel, thoroughly wash and sieve it until all bits of debris and waste have been removed. To clean the aquarium ornaments / artificial plants, simply wash and scrub them under tap water.
  6. Now that everything’s nice and clean, you can put the gravel back in, replace any ornaments and artificial plants, and then start adding the water. Add the percentage of aquarium water that you originally took out, then add the batch of freshly prepared water. Let the system filter for about 10 minutes. Check the temperature is sitting correctly — if all is good, add your betta back into the aquarium. If the filter cartridge is also due to be changed, now is a good time to do it.

An important note: this is a very thorough method of cleaning the aquarium. This method isn’t necessarily required every time you do a clean; there are less thorough methods of cleaning an aquarium, which we detail below in relation to cleaning a complex aquarium. If performing a thorough clean, bear in mind that you don’t want to rid of any of the beneficial bacteria in the aquarium when giving a clean this thorough. So be SURE to keep a percentage of the original aquarium water as suggested.

Also, many of the beneficial bacteria live in the filter media within the filter (unless it’s replaceable media like carbon or charcoal). In order to stop the media from drying while you clean, either make sure the filtration media compartment is filled with water (if it retains water after the water level has decreased) or take the media out and submerge it in a container of the aquarium water.

Some Good Aquarium Vacuums To Choose From:


Aquarium Siphon Vacuum by Laifoo (view it here on Amazon)

A simple design with simple components and easy to use.

Aquarium Gravel Cleaner Siphon by VIVOSUN (view it here on Amazon)

Aquarium Gravel Cleaner by Hygger (view on Amazon)

My Aquarium is Complex! How Do I Clean it Without Removing Everything?

If you have a complex aquarium,  you WILL need water prepared for topping up the aquarium after the process of cleaning. The water lost during the clean (removed via the vacuum) will be dirty and  and we recommend you do not reuse it.

Some aquariums can be more than just a bit of gravel and ornaments. They can be heavily planted, carefully arranged, and can contain more than just a betta, so it can be a pain to move everything for the clean. However, cleaning the aquarium without the removal of everything can be done without great difficulty; here’s how.

Firstly you’ll need two basic things: an aquarium gravel cleaner / vacuum (we've listed a few good options here) which can also be called an aquarium syphon and an aquarium scrub (magnetic, if possible). Once you have those in hand, you can do the following:

Depending on how much water you plan to remove from the aquarium when following the method below, you may or may not want to remove your betta from the aquarium. If you do wish to, remove the betta from the aquarium using a net or cup. It’s fine to hold the betta in a large mug (or something similar) with some water from the aquarium whilst you clean. Cover the temporary container so that your betta can’t jump out.

  1. A gravel cleaner vacuums the gravel, removing any waste or debris. Gravel cleaners can be powered / motorised or can work like a siphon. They are a long tube-like structure with two ends: the vacuuming end (this is placed in the gravel) and the output end (this is where water carrying debris comes out — it should be placed in a bucket). Simply place the vacuum column in the gravel. If your cleaner is non-motorised, to start suction you may need to slightly shake the column (this is to do with the science of syphoning). How this works will be stated on instructions that come with the cleaner.
  2. Once the cleaner starts to suck, move the column throughout the gravel. The cleaner won’t carry the gravel away but will vacuum up any light debris and waste in the gravel. It will, however, remove water from the aquarium. Vacuum the gravel around any plants or ornaments and try to clean the gravel the best you can without causing disruption to the aquarium layout. The movement of the gravel will bring up debris into the water, but if you have a filter it will catch the debris.
  3. Once the gravel looks thoroughly clean, consider the walls of the aquarium. If they need a scrub, use a magnetic aquarium scrub to remove any dirt or algae. You can scrub it off if you have a non-magnetic aquarium scrub.
  4. At this point, the water in your aquarium  may look filthy. When you push the syphon through the gravel, sometimes not all of the waste gets vacuumed up. This is fine; a good time to clean your aquarium is when you’re coming up to a water change. When cleaning the gravel, the cleaner will remove a percentage of the water. Bear in mind the longer the cleaner is in the aquarium, the more water it will remove. You won’t be able to replenish the aquarium with the water removed by the cleaner as this water contains large amounts of waste. If you’re planning to do a large percentage water change, remember you MUST prepare the water in advance. Anything more than a 50% water change must have water prepared in advance.
  5. Allow the aquarium to sit for 10 minutes so the filter can remove any debris. Re-add the percentage of fresh water needed. It’s a good idea to change the filter cartridge at this stage too, as this will help with the removal of extra debris.

To note: depending on the strength and size of the vacuum it may actually be a good idea to remove the betta from the aquarium. We’ve never heard anyone say that their betta has been sucked up a gravel vacuum whilst cleaning but it’s best to be cautious. The piping on most aquarium vacuums isn’t large enough to suck up a betta anyway. Just be wary when cleaning with your fish in the aquarium.

Some Good Aquarium Scrubs To Choose From:


Algae Cleaning Magnet by Aqueon (view it here on Amazon)

Available online, cheap and effective.

Acrylic Aquarium Special Mini Magnetic Cleaner by Carefree Fish (view it here on Amazon).

hygger Aquarium Magnetic Glass Cleaner (view it here on Amazon).

Watch us clean a betta fish tank

Our Bettaboxx Premium membership includes a video course where we show you how to set up a betta tank from start to finish. 

The course includes a video on aquarium maintenance and how to clean your betta fish tank.

You can find out more about our premium membership here.

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