Here’s Why Betta Fish Need A Filter

Most pet stores house their betta fish in small containers with no filters. They only change the water every day or two to keep the container clean. There are often tiny bowls or tanks sitting below the row of bettas, claiming to be the perfect home. There are no filters in sight.

These too-common scenarios are the reason many bettas live in unideal conditions.

Betta fish need a filter in their aquarium like any other fish.

Filters are ideal homes for beneficial bacteria that get rid of toxins and make the water safe. They suck up large waste particles, keeping the tank clean between water changes. They also produce currents that provide fish with oxygen.

As fish with labyrinth organs, bettas can survive in somewhat dirty, stagnant water for a time. Simply because they can survive does not mean they are happy or healthy. It is a misconception that bettas can live in a bowl without a filter to keep their space clean.

Bettas that have a filter in their tank have cleaner homes. They are healthier, less likely to get sick, and often live longer lives.

Do Betta Fish Need A Filter?

Betta fish need a filter in their tank, despite what some resources say. Filters keep the tank clean, safe, and stable.

Filters Keep The Aquarium Safe

The primary purpose of filters is to provide a home to beneficial bacteria in the tank. The bacteria break down ammonia, nitrites, and nitrates in the tank. Breaking down these toxins makes the aquarium safe for the inhabitants.

Without beneficial bacteria, waste continues to build, creating a dangerous environment.

Little bacteria live in the water column; most live in the filter and substrate. Sponges, filter floss, and similar materials make up much of the filter. They are ideal places for beneficial bacteria to live.

The Nitrogen Cycle

New tanks go through the “nitrogen cycle,” the process of building beneficial bacteria.

New tanks have no beneficial bacteria, causing the ammonia levels to spike. As the bacteria develop, the ammonia levels drop, and the nitrite levels spike. Eventually, the bacteria convert the nitrites to nitrates. Nitrates are far safer for fish, though they are toxic in high quantities.

Enough beneficial bacteria are in the tank once the nitrogen cycle is complete.

Filters Keep The Aquarium Clean

Filters help keep the aquarium clean between water changes.

Hobbyists keep large materials inside the filter, like sponges or filter floss. These materials catch large waste, like fish food and poop, that the filter sucks up. The waste gets stuck in the sponge or floss, preventing it from returning to the tank.

Some filters are large enough to hold chemical filtration, like activated carbon. Chemical filter media helps keep the water clean by reducing toxins like ammonia.

Filters Provide Oxygen & Currents

Filters provide oxygen and flow to the aquarium by creating surface agitation. The more surface agitation the filter creates, the more gas exchange occurs. The more oxygen enters the water, the more surface agitation the filter creates.

Why Do Many Think Bettas Can Live In A Bowl?

There are several reasons new hobbyists might believe bettas can live in bowls. It’s something everyone has heard for years. Mainly, the myth stems from misconceptions about their natural habitat and labyrinth organs.

Pet Stores Sell Bettas in Tiny Cups

Most pet stores sell their betta fish in tiny cups with less than one gallon of water. These cups protect the bettas from each other until they go to their permanent homes. Many don’t know these containers are meant to be temporary.

Pet Stores Sell Tiny Bowls For Bettas

It doesn’t help that pet stores profit from these misconceptions. Many (not all) pet stores sell tiny bowls and “tanks” marketed for bettas.

Many have asked, “If bettas can’t live in small containers, why do pet stores sell tanks that small?” It comes down to profit and selling as many bettas as possible.

Bettas Live In Puddles (Myth)

Newbies also have misconceptions about bettas’ wild habitat.

We’ve heard it before, “Bettas live in small puddles in the wild, which means they can live in bowls.” While there’s some truth to the statement, the information is lacking.

Bettas only live in small puddles of water during the dry season. Their habitats dry out, and they sometimes get stuck in puddles.

Their labyrinth organs allow them to breathe air from the surface so they don’t die.

Bettas don’t live this way forever. Unfortunately, many bettas die during the dry season because puddles are unsuitable. To survive, bettas hop from puddle to puddle, looking for larger bodies of water.

Bettas Live In Expansive Rice Paddies (Truth)

During the wet season, bettas live in wetlands and rice paddies.

These water bodies are shallow, though they aren’t small. These watery habitats stretch on for miles, giving more than enough space for bettas to swim.

Here’s What Happens When Bettas Don’t Have A Filter

Without a filter, there won’t be enough beneficial bacteria to break down toxins in the tank. While some beneficial bacteria live in the gravel, most live in the filter.

A tank or bowl without beneficial bacteria cannot get rid of ammonia or nitrites. The toxins in the water accumulate, becoming increasingly dangerous for the fish.

Filters aren’t only homes for beneficial bacteria. They also get rid of large pieces of waste, like food and poop, through mechanical filtration.

Without a filter, poop and leftover food will sink to the bottom and collect in the gravel. Not only does it break down into ammonia and nitrites, it also makes the aquarium look disgusting.

Tanks high in toxins are dangerous for fish, causing illness and death. Bettas can suffer from ammonia poisoning, bacterial, parasitic, and fungal infections.

Treating a sick fish in a tank without a filter is also more difficult than in a filtered tank.

Why It’s A Bad Idea To Skip The Filter

Tanks or bowls without filters need considerable cleaning to be somewhat “healthy.”

We don’t recommend skipping the filter, even with extra cleanings. Tanks are time-consuming, difficult to maintain, and not as reliable without a filter. Frequently removing large amounts of water can also shock the fish.

With a filter, hobbyists only need to clean the tank once every one to two weeks, depending on the tank size. Cleaning a cycled and filtered tank takes about 15 minutes. The tank is a mini ecosystem that is mostly able to maintain itself.

Without a filter, hobbyists must clean the tank or bowl and change the water several times a week.

Can You Use Aquatic Plants As Natural Filters?

Using a plant(s) as the only form of filtration is not enough to keep an aquarium or bowl healthy.

Many new hobbyists hear they can buy a vase for their betta fish and use a plant as a natural filter. The betta fish lives in the bottom of the vase, and the plant grows from the top with only its roots in the water.

Plants are great for creating oxygen and removing toxins from the water. Unfortunately, no plant can keep up with the amount of waste a betta produces.

These types of environments simply aren’t healthy for betta fish. Don’t fall for the appealing look of these betta vases and invest in getting the proper equipment for a betta fish.

Choosing A Filter

Choose a small filter that easily fits in the betta’s tank and is strong enough to keep the aquarium clean. A filter with little flow is necessary for bettas. Their long, flowing fins cause them to be weak swimmers.

Sponge Filters

Sponge filters are our favorite choice for bettas. They are small, have plenty of space for beneficial bacteria to grow, and produce little flow.

Hang-Over-Back (HOB) Filters

HOB filters are another option for bettas, though they’re best for tanks 10 gallons and up.

The tricky thing about HOB filters is that they are often too strong for bettas. The suctions of the intake valve may suck up the betta’s fins. Bettas may become stuck on the intake valve, causing fin tears that can lead to infection.

The current from the filter may be too strong, making swimming difficult.

Hobbyists must often make modifications when using a HOB filter for a betta.

Place a sponge over the intake valve to prevent the betta’s fins from getting stuck. Use a baffle at the top of the filter to slow down the current.

Under-gravel Filters

As their name suggests, under-gravel filters sit under the substrate. They suck the water in through the gravel and pump healthy water back into the aquarium.

These filters are good for bettas because they are gentle and produce little flow.

Which Kind Of Filter Is Best?

We recommend using a sponge filter for betta fish. They are great for filtering waste and harboring beneficial bacteria. They are better than under-gravel filters at removing large waste particles.

Sponge filters need an air pump to operate. Pick an adjustable air pump and keep the flow low so it doesn’t bother the betta.

Sponge and under-gravel filters are safer than HOB filters. They won’t suck the betta’s fins into the filter. They usually need less adjustment than HOB filters.

Sponge filters are inexpensive compared to HOB and under-gravel filters.

Recommended Filters For Betta Fish

1. Upettools Sponge Filter

Ideal for 5 to 10 gallons, this filter has a single sponge and a compartment at the base for bio media. It is small enough that it doesn’t take up much space, though it’s large enough to filter water properly.

Pros:

• Long and sleek design with suctions cups to adhere to the side of the tank easily
• The sponge has a lot of surface area — ideal for establishing beneficial bacteria
• Removable sponge for easy cleaning
• Includes ceramic media balls
• Affordable

Cons:

• Air pump not included
• Too big for some aquarist’s tastes
• Not powerful enough for tanks larger than 10 gallons

2. Aquaneat Corner Sponge Filter

Corner sponges offer a space-saving advantage that regular sponge filters do not have.

Corner filters work like other sponge filters. They are triangle-shaped to fit in the corner of the tank. Many hobbyists prefer these to traditional sponge filters since they occupy less space.

Aquaneat’s sponge filters come in a few varieties. Hobbyists can choose the simplest filter, which only contains a sponge. They can also get the “air-driven bio corner filter” with a bio media compartment.

Pros:

• The small, triangular shape takes up little space
• Easy to hide
• Ideal for aquariums of up to 10 or 15 gallons
• Includes an air infusion chamber for better oxygen solubility
• Low flow for bettas’ delicate fins
• Easy to clean

Cons:

• Little surface area for beneficial bacteria growth
• Air pump not included
• May hold onto air bubbles that cause it to float
• May be too loud

3. Penn Plax Premium Under Gravel Filter

These under-gravel filters come in small sizes, ideal for most betta fish tanks. The holes for water intake are large enough to suck up large waste particles. They are not large enough to suck up gravel.

Pros:

• Several sizes for smaller and larger tanks
• Adjustable intake tubes for tanks of varying heights
• Easy to put together
• Contains air stones for better water flow and oxygen solubility
• Compartments for activated carbon
• Affordable

Cons:

• Does not hold beneficial bacteria as well as sponge filters
• Large waste particles may not make it to the filter
• Air pump not included
• Fragile

Do Betta Fish Need A Heater?

Heaters are almost always necessary for betta fish tanks as they are tropical fish.

Bettas need a water temperature between 75-81°F ( 23.9-27.2°C). Most hobbyists live in environments with fluctuating temperatures. They cannot maintain these temperatures without a heater.

Some exceptions are those that live in tropical environments with hot, stable temperatures.

Cold water causes a betta’s metabolism to slow down. A slow metabolism can cause constipation and swim bladder problems. It also hinders the betta’s immune system and leaves it more likely to become sick.

How To Set Up A Good Betta Tank

Setting up a good betta fish tank that keeps the fish happy and healthy is easy. With some research, new betta owners can avoid making many common mistakes.

Here are some tips:

• Avoid bowls — bettas need at least 5 gallons of water
• Use a filter
• Use a heater
• Maintain a temperature between 75-81°F (23.9-27.2°C)
• Maintain healthy water parameters
  • Ammonia: 0 ppm
  • Nitrites: 0 ppm
  • Nitrates: <40 ppm
  • pH: 6.5-7.5
• Test the water often
• Provide decorations — live plants, driftwood, & other non-sharp items
• Feed nutritious, protein-packed foods
• Know which tank mates work with bettas & how to create a happy home for them all.

How Often Should You Clean A Betta Fish Tank With A Filter?

Betta fish tanks with filters need cleaning about once every one to two weeks. Hobbyists should clean 5-gallon tanks once a week; the waste accumulates more quickly. Tanks 10 gallons and up are usually okay with biweekly cleaning.

The filter itself usually needs cleaning about once a month. Be careful not to overclean and kill off the beneficial bacteria.

FAQs

How Long Can A Betta Fish Live Without A Filter?

How long a betta fish can live without a filter depends on how well the hobbyist cares for its tank. Some bettas can live several years, while others die after a few weeks or months.

Remember that a fish may live a few years without a filter, though it is likely still stressed.

An unfiltered tank with a heater is better than a tank without one. Likewise, it’s better to clean an unfiltered tank three times a week than once weekly. An unfiltered tank with live plants will also be healthier than one with fake plants.

All the above factors contribute to how long a betta fish may live in a bowl or tank without a filter.

Do Betta Fish Need An Air Pump?

Hobbyists using a sponge or under-gravel filter need an air pump for the filter to operate. The air pump pushes air through the filter, helping it aerate the water and pull waste through it.

Those using a HOB filter won’t need an air pump.

Some hobbyists attach air pumps to bubblers, which provide more flow and oxygen to the water. Betta fish DO NOT need bubblers. They will have trouble swimming.

Do Betta Fish Have To Live Alone?

Most betta fish do not have to live alone; several species work well with betta fish. Bettas usually do well with similar-sized peaceful fish. Choose fish with short fins and dull colors.

Some good tank mates include:

• Neon tetras
• Ember tetras
• Corydoras catfish
• Snails
• Platies

Some betta fish are more aggressive than others and may have to live alone, though this isn’t super common.

Never keep two male betta fish together — they will kill each other. Females can sometimes live together in sororities. Sororities are challenging to maintain — only expert betta keepers should attempt them.