betta fish in a clean tank

Cleaning Betta Fish Tank: Everything About the Cleaning Process

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Every fish tank requires maintenance; some require more than others, but whether it’s a water change every week or topping a tank off every month, the success of most tanks is the reflection of how much time you give them.

Regular water changes, substrate vacuumings, and filter media replacements are just some of the most common steps you will need to take to keep your tank stable. Luckily, these processes aren’t hard and usually lead to a thriving ecosystem.

Keep reading to find out why you need to clean your betta fish tank and how to make sure you’re doing it right!

The Basics

It might seem like betta fish are one of the easiest pets you could own, but like any other animal, they still require care and upkeep.

Cleaning up after betta fish isn’t as simple as cleaning up after a dog or cat; you need some practice and the right tools to get it right.

But first, you need to understand why a clean tank is necessary in the first place!

Why Do You Need To Clean Your Betta Fish Tank?

For the most part, fish tanks are self-sufficient ecosystems that take care of themselves with the help of nitrifying bacteria, converting ammonia to nitrates.

In order to understand why you need to clean your tank, you need to place your small enclosed ecosystem in the context of your betta’s natural environment in the wild.

In wild aquatic habitats, there is a constant importation and exportation of nutrients/minerals, wastes, and gasses, due to flowing water, sediments, evaporation, rain, and the influence of various flora and fauna.

In our small fish tanks, there is no input other than what we introduce into the system, and export is typically what’s soaked up by filter media and absorbed by aquatic plants.

Hobbyists have solved this problem by performing weekly or biweekly water changes. Water changes allow new nutrients and minerals to enter the system while getting rid of those built up over time.

For example, nitrates. Nitrates are constantly being created through the nitrogen cycle that converts ammonia to nitrite to nitrate.

As nitrifying bacteria do not process nitrate, it is left to build up in the tank and can become toxic at extreme levels.

While plants and algae take up nitrates, hobbyists will usually still need to perform water changes to keep the nitrates in their tanks at a safe level.

Similarly, water changes help replenish oxygen levels within the tank. Usually, surface water agitation by way of a filter, air stone, or powerhead increases gas exchange.

Water changes help create movement through the tank and introduce new gases through the new water.

Since pH is affected by minerals leaching from your rocks and substrate and how much carbon dioxide is in the water, water changes can also help stabilize your aquarium’s pH.

How Often Do You Need To Clean Your Betta Fish Tank?

While all these elements seem like a delicate balance, water parameters in mature tanks can stay relatively stable when small water changes are regular, and aquarium maintenance is tended to.

That being said, how often you need to clean your betta fish tank depends on the tank itself.

How often you need to do a water change depends on the size of the aquarium, filtration, the bio load of your fish, feeding habits, and more.

As a general rule, doing a 10% water change every week or 20% every two weeks is recommended.

Some hobbyists are able to get by only doing a larger water change once a month, but we’d only recommend this in larger, well-established aquariums.

In a nano tank or any aquarium that’s less than a year old, there just isn’t enough stability in the tank’s ecology to handle regular large water changes.

Algae Problems

If your betta tank starts growing algae, it is usually recommended to increase the frequency of water changes to help remove excess nutrients; at the same time, it is also important to search for the cause of the excess nutrients.

Algae is usually the result of high nitrates or phosphates and too much lighting and/or the wrong light spectrum.

man cleaning aquarium using magnetic fish tank cleaner

How To Clean Your Betta Fish Tank

So it’s time for your first routine tank cleaning! It can be a little scary, but after a few tries, you’ll be able to perform a water change in a short amount of time with little to no hiccups along the way!

Here are the easy steps involved with cleaning your betta fish tank (order may change with personal preference):

  • Prepare new water. When you clean your betta tank, it is usually recommended to have the new tank water prepared and ready to go. This will mean heating the water to match the temperature of the tank and adding a de-chlorinator. At the same time, you may also unplug any equipment in the aquarium so that they don’t burn out and there is no danger to yourself.
  • Start a siphon. Once your water is ready and all equipment is safely turned off, it is time to start taking water out of the tank. This can be done by using an aquarium vacuum or airline tubing. Alternatively, you may also use a cup to remove portions of water slowly.
  • Scrub for algae. While siphoning water, you may also take the time to scrub the sides of your aquarium, removing any algae you can see. This is so that if larger pieces of algae come off, they will be sucked up and removed from the tank. A magnetic algae cleaner or aquarium-safe sponge is ideal for this.
  • Vacuum the substrate. Using this time to vacuum and clean the substrate is also a good idea. Cleaning the substrate will keep dead zones and detritus from piling up, leading to algae problems or other excess nutrients. Overturning the substrate will also help with gas exchange.
  • Waft hard-to-reach places. If you have decorations close to the wall of your tank or areas where water flow isn’t good, make sure to waft water into those areas to flush out debris gently. Many hobbyists use turkey basters for the same effect. It may also be a good idea to vacuum the surface of the substrate or use a fish net to catch loose particles afterward.
  • Save some spent water to wash filter media later. Filters should never be washed under tap water since it kills most of the important nitrifying bacteria within the media. Instead, save a bucket full of spent water from washing the sponge a few days after your water change. Never clean the filter and the tank simultaneously since this would decimate too many beneficial bacteria in one go, shocking the whole tank’s ecology and your betta.
  • Stop siphon. Once you have cleaned the tank as much as you can (while not disturbing too much too fast), you may stop the siphon. Make sure not to leave your tank empty for too long as the microbes and algae living in areas exposed to air for too long will start to die off, creating more ammonia.
  • Refill the tank. Once you have finished scrubbing the sides of the tank, vacuuming the substrate, and wafting hard-to-reach places, it is time to refill the tank with the water you’ve prepared. While betta fish should be able to withstand little changes in water conditions, it is best to go slow with this process. Make sure to double-check the temperature and gradually refill the tank with the remaining water. Once done, equipment may be turned back on.

The best time to clean the aquarium is during water changes. It is recommended to avoid putting your hands in the tank as much as possible otherwise, each time that you do, you risk contamination and stressing out your livestock.

However, if you’re struggling with algae, you might have to reach within the tank at other times regularly.

Note: Remember that betta fish are tropical fish and require tropical water temperatures. New aquarium water must match the tank’s temperature and not stress out your aquarium inhabitants. Room temperature water can really stress out your fish if it is too hot or too cold!

Also, remember that your heater will be unplugged while performing water changes, so room temperature can start to affect the temperature of your tank, depending on how long the process takes.

Try to clean the tank as quickly as possible to avoid temperature changes and unnecessary stress to your fish.

Products To Avoid When Cleaning Your Betta Fish Tank

Water changes require no additional chemicals other than a simple dechlorinator or ‘water conditioner’; no other chemicals are needed.

However, when setting up a tank, most beginners want to clean their tank before they fill it up with water. Betta fish like clean and fresh water. 

Too many times, they use soap to clean the tank. This is not a good idea since soap residue and detergent can seriously harm or even kill your betta fish.

Even small amounts of soap or detergent will affect your betta fish. In short, soap interferes with gill functions, leaving your fish to drown. This can happen very fast but is easily preventable.

If you have an aquarium, or any other aquarium equipment or accessories, that you know has been in contact with soap, quickly remove up to 80% of the water and refill the tank; you want to dilute the soap as fast as you can.

Repeat this process several times; adding activated carbon may help remove the soap. This ensures good water quality in the tanks. 

When cleaning an established tank, it is always best to rinse as much as you can off with spent aquarium water. However, when starting a new tank, you may want to clean it before filling it with water.

Luckily, a few products are much less harmful than soap and just as easy to get. For instance, soft brushes can help food waste in the tanks. 

Proper fish care starts by ensuring awesome water quality, the appropriate concentration of ammonia, creating an enriching environment, and, finally, creating a conducive aquatic environment. 

Diluted white vinegar is a good alternative for cleaning most aquarium accessories and decorations. Simply mix 1:1 of water and white vinegar, rinse, and/or soak.

Make sure to rinse the objects that were cleaned a couple of times to ensure that there is no vinegar residue; while unlikely if rinsed well, vinegar can also affect pH levels.

When in doubt, just use warm water. This is especially true for new setups where you can still dry off surfaces, so that tap water doesn’t remain in your system.

Note: Remember that this applies to any equipment that is also used to clean your aquarium, like the aquarium vacuum and any buckets!

Why Is Your Betta Fish Tank So Dirty?

There are a few reasons why you might find that your betta fish tank is especially dirty. Some of these possible causes are overfeeding, poor aquarium maintenance, and a poor source of water.


Betta fish are easy to overfeed as they’re always willing to accept food. It is important to have a routine with a set amount of food ready to go to prevent overlapping feedings.

Feeding twice a day and only as much as your fish can eat within 1-2 minutes is a good rule of thumb for feeding your betta.

All uneaten food should be removed from the tank within a few minutes of feeding, and food rationing should then be reconsidered. The debris left in the tank may develop dangerous bacteria, which may affect the betta fish aquarium. 

Overfeeding can quickly lead to algae problems if left untreated. It is best to regularly clean the substrate and filter sponge/pad to ensure food isn’t getting stuck and leaking nutrients.

Poor Aquarium Maintenance

Perhaps you are feeding your betta fish the recommended amount, and there are little to no leftovers, but you don’t regularly clean your fish tank.

As discussed, a lack of water changes will lead to nutrients, like nitrates and phosphates, quickly building up and leading to cloudy aquarium water, algae, or both.

Usually, cloudy water can be cleared up relatively quickly with water changes and a good deep cleaning, but sometimes a UV sterilizer is useful for larger tanks.

Algae is more of a headache and can take several weeks to months to clear up manually. Luckily there are a few tankmates who can help with this, who we’ll talk about in a moment.

Poor Source of Water

Maybe your problem doesn’t stem from overfeeding or poor aquarium maintenance; maybe your problem is at the source.

Tap water might be convenient and readily available for a fish tank for a betta, but it is not the best choice for the tank’s longevity.

Tap water is usually filled with many unknowns, from nitrates to heavy metals; the only way to definitively know what is in your tap water is by getting a laboratory test that can be quite expensive.

Reverse osmosis (RO) or distilled water helps remove most impurities from the water, helping prevent future complications with water parameters and algae.

Alternatively, live aquatic plants can be a good way to filter out potentially dangerous compounds from your water. Ensure you fill your aquarium with tap water to ensure a healthy tank for your fish. 

Some Natural Alternatives

As you can see, betta tank ecology and cleanliness is a complex science! There are mixed opinions, even among experts, regarding the best protocol.

Some betta enthusiasts claim that tank cleaning is ultimately unnecessary if you master maintaining a healthy, balanced ecosystem within the aquarium.

This is perhaps a better option for the more advanced hobbyist since it requires a deep understanding of how the different elements like bacteria, algae, substrate, filter, plants, and your fish interact.

Live Plants

Aquatic plants are nature’s way of keeping her water clean. Plants extract nitrates, phosphates, and even heavy metals from the water, which would otherwise become toxic to fish or lead to deadly algae blooms.

Plants are so good at this that environmentalists are now using plants to extract, sequester and/or detoxify pollutants from water systems that have become contaminated in a process known as ‘Phytoremediation.’

Plants are ideal agents for water remediation because of their biochemical and physiological properties. It’s what they have evolved to do!

Amazon Frogbits, Hornwort, and Anacharis are all excellent for water purification and can quickly turn excessive nitrates into beautiful, luxuriant growth.

Betta Tankmates – A 24-Hour Clean-Up Crew

It’s not just plants that can help clean up a betta tank. Many fish species, especially bottom-feeders, are adapted specifically to the role of cleaners in the ecosystem.


Corydoras catfish, Plecostomas (or ‘Plecos’), Khuli Loaches, and Upside Down Catfish all do a wonderful job digging through gravel, grazing rocks, driftwood, and even cleaning your aquarium glass!

A small shoal of Cory cats is especially fast at finding food that’s fallen to the bottom of the tank and hoovering it up before it decomposes. They’re also very interesting fish to watch in their own right.


For this role, many betta owners also keep various species of shrimp and snails in their tanks. Cherry shrimp, Amano shrimp, and Ghost Shrimp are all popular shrimp species for cleaning up pieces of uneaten food from the bottom of your tank.

Shrimps are also brilliant for cleaning up algae and biofilm.

Snails are also superb algae eaters and are especially good at keeping your tank’s glass clean. Mystery Snails, Nerite Snails, and Apple Snails are all popular choices.

While invertebrates might not seem as exciting as fish, getting to know a pet snail or shrimp can be surprisingly rewarding.


Betta fish are relatively easy to take care of, but that doesn’t mean that they require less maintenance than other tropical species.

Before buying your first fish, ensure you know how to clean a betta fish tank and all the maintenance that goes into keeping your tank in optimal condition.

Also, consider using nature’s clean-up operators like live plants, bottom-feeding fish, and invertebrates to help keep your tank clean and healthy.

If you have any questions about why you need to clean a betta fish tank, how to clean a betta fish tank, or have had experience with a particularly dirty betta, don’t hesitate to leave a comment below!

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