Betta fish Laying at the Bottom of the Tank: 12 Reasons Why

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Betta fish owners will witness all kinds of weird behavior.

Betta Laying At Bottom Of Aquarium By Blehblehblehblehbaba

Still, a betta that’s laying on the bottom of the tank does sound alarming.

Is the fish turned on one side or are its fins supporting its body?

Is that a symptom of a serious illness or just another odd trait of character?

Will it be okay eventually or is that the final straw?

Why does it look as if your betta is breathing heavily?

A Betta fish may rest on the bottom of its tank due to polluted aquarium water. Foul water conditions can make Betta fish lethargic and even poison them. Another common reason why Betta fish don’t move from the bottom are strong filter currents that impair their swimming ability.

However, sometimes it’s completely normal for betta fish to stay at the bottom of the tank especially if they’re old.

Let me explain.

12 Reasons why your betta fish is laying at the bottom of the tank

A healthy betta needs its personal space, frequent water changes, and a properly diversified diet.

When all of the above conditions are met, bettas rarely spend any time on the bottom.

So if your betta is standing still in an unnatural position, this could mean a number of things.

Here are 12 reasons why your betta fish might be laying on the bottom of the tank:

1. It may be sleeping.

Betta fish, like most other animals, do need rest and will sleep.

They will often find a comfortable place on the bottom of the aquarium where they will lay and take a nap during the night.

Sometimes a betta will snooze on a big leaf, closer to the top of the tank, as that’s where they do it in the wild.

Betta fish are not nocturnal, so their sleeping habits dictate being active during the daytime and going to sleep at night, or when the room gets dark.

They may also sleep in portions of about 1 hour at a time, multiple times a night.

Betta fish like to sleep lying on their side.

It’s an interesting trait of theirs adding to their popularity among fishkeepers.

If your pet friend appears otherwise healthy and active, it is probably just taking a nap on the bottom.

Fun fact: There are even “betta beds” that act as artificial leaves, large enough to support a resting betta. Amazon has them for under $4.

Anyway, if you’re like me (amused at how absurd it looks) then you’d be happy to give your pet a comfy bed.

The leaf should be mounted at the top of the tank.

Closer to the surface is where Betta fish spend their time in the wild.

Caution: Don’t mistake sleep with exhaustion.

A betta will go to sleep whenever the lights are off.

Keeping them on constantly can confuse the fish.

It will swim around until it’s exhausted and then have a prolonged rest somewhere in the tank.

Exhaustion can weaken your betta’s immune system.

2. It has Nitrate poisoning.

A metallic blue Betta fish swimming in a fish tank

by in-another-castle

Long-term exposure to Nitrate is one of the if not, the most common reason behind a Betta fish that’s lethargically lying on the bottom of its aquarium. Is your Betta fish also progressively losing its coloration and beginning to look pale?

Is it lacking appetite? Do its gills move rapidly as if the fish is out of breath?

If you notice a combination of these signs then it’s very likely that your Betta spends its time on the tank’s bottom because it has been poisoned by the Nitrate content in its aquarium water. If you click the link you’ll learn everything about that condition and how to immediately treat it, but I’ll give you a quick rundown.

Prolonged exposure to even 20 ppm (parts per million) of Nitrate will sooner or later cause signs of illness. You’ll hear most aquarists say that anything between 20 and 40 ppm is safe to have in a freshwater aquarium.

This, however, is a common misunderstanding that originated from the fact that nitrate is relatively less harmful when compared to nitrite and ammonia.

Both ammonia and nitrite are extremely toxic to aquarium fish, where nitrate is more of a silent, slow killer.

Arm yourself with a reliable liquid test kit and perform a water test.

Test strips can only give a rough estimation of the situation but are nowhere near accurate.

In the case of poisoning, you’d need to know exactly how much Nitrate is there in the Betta fish tank.

This is so because you’ll need to calculate how much water you’ll need to remove. A good water test to precisely measure the Nitrate in an aquarium would be the API Master test kit (this link leads to Amazon.com).

At this point, you’ll need to physically remove the Nitrate through water changes but do so in a slow and controlled manner.

Changing too much aquarium water at once may cause shock to your Betta fish.

3. It’s lazy.

Red Betta fish laying on the bottom of a fish tank next to decoration

by coo_guy82

Sometimes, it’s not a lack of sleep but rather a lack of motivation.

If the front pelvic fins are moving and supporting a Betta that’s sitting on the bottom of its tank, then the fish is most likely being lazy.

Laziness is a common trait of ornamental Betta fish.

Having huge fins is not always fun for swimming, so the fish eventually develops a habit of chilling at random places in the aquarium, and more often than not, this happens to be the bottom.

Monitor the behavior of your fish.

If your Betta moves around and feeds normally in-between “rests” then there’s nothing you should worry about. Anyway, getting one of the Betta hammocks I mentioned above will provide your fish with its own resting space, away from the bottom.

4. It has a malfunctioning Swim Bladder.

Red betta with a swollen swim bladder near a piece of driftwood

by TottandBean

Another reason for a Betta to remain on the bottom or even swim sideways may be the swim bladder disorder (click the link to check the extensive guide I wrote on that). The Betta fish’s swim bladder is narrowed due to overfeeding or constipation, among other reasons.

The stomach swells, hindering the swim bladder’s proper functioning.

The condition is not lethal in its nature but it makes swimming really hard for the fish.

Sometimes a Swim Bladder malfunction causes Betta fish to spend a lot of their time laying around the bottom, as they find it difficult to move.

They may also float uncontrollably to the top, but still turned sideways or even upside-down.

The disease can be treated by fasting the fish and feeding it foods that contain more fiber.

An approach I find extremely effective is to feed the betta a crushed pea or some Daphnia, which are both an excellent source of fiber. For the former – peel the pea and boil it before the offering.

You should fast the fish for at least 1 day (24+ hours) after that.

Be sure to clean the tank of pea leftovers, as cooked peas can make a mess in the aquarium’s water.

Using Daphnia is pretty straightforward and the preferred choice among aquarists.

Personally, I also prefer to feed my Betta some Daphnia as it is a natural source of fiber. Betta fish are carnivorous and that’s what they would eat if they were in the wild.

To avoid constipation and, consequently, Swim Bladder malfunctions I recommend feeding your Betta with high-fiber foods at least twice a week. The other type of bloating can be avoided if you soak any pellets for 2 to 3 minutes or so before feeding them to your Betta fish.

This allows the food to swell outside of the fish’s stomach.

Don’t forget you need to soak them in aquarium water, or at least one that has been dechlorinated. For extra constipation-prevention diversify your Betta’s menu by feeding it bloodworms (a type of water flea larvae) occasionally.

Bloodworms are another food that replicates the natural diet of a Betta fish. An organic diet may help it fight off disease and make its bright colors stand out more.

5. Filter current is too fast.

Fantail Betta fish next to the aquarium filter

by Kenzielauren8

Some may argue that Bettas don’t really need a filter because they can get tired quickly if the output current is too strong for their oversized fins. Though the part about Betta fish not needing a filter is wrong, it’s definitely recommended to go for a sponge filtration in smaller fish tanks of 5 or fewer gallons.

That’s unless your aquarium kit comes with a built-in filter, which usually isn’t too strong.

Most selectively bred Betta fish have massive fins that make swimming in more turbulent water difficult.

So if your Betta seems less active and prefers to relax on the bottom of its tank, try tuning down the filter’s water circulation.

Not every filter has a flow-controlling valve, but many do. My success for a 10-gallon single Betta tank has been with this such one filter (link to view it on Amazon) which has the adjustable flow feature.

Being able to control the flow in a small tank has made my pet friend twice as active. For small fish tanks that hold between 3 and 5 gallons of water, you can likely get away with using a cheap sponge filter such as this one.

For my larger tanks that include a betta or other community fish with large fins, however, I am quite satisfied with using the AquaClear Power Filter 50. In my opinion, the last one crushes the competition on price tags that come with the same functionalities.

Both HOB filters work pretty well with my super poly-fil hack, by the way (link goes to my article on that). Anyway, if you can’t get a filter with an adjustable flow rate right now, there are several DIY approaches you can try:

  • Strap a bio bag or any other kind of filter media on your filter’s water outlet. You can use a rubber band, fishing line, or a cable zip tie to secure its placement.
  • Disperse the flow from the filter. Although you can get awfully creative here, I can confirm two easy and efficient ways to do that:

    – Tank divider kits are super cheap and will provide you with the perfect flow baffle and the means to attach it. Mount the mesh in front of the flow outlet.

    – Use a brand new plastic soap dish. Soap can be toxic to fish, so go and get a new cheap one from Walmart. They usually come with holes that are perfect for spreading the flow of your filter. Of course, go for the ones with suction cups.

  • Block the flow with plants or decoration. A well-planted tank will provide a safe place for your betta, away from the mean filter flow. You can also block the current with rockwork or artificial caves.
  • Drill holes in the intake pipe of your filter. This is simple physics. More holes or a larger intake pipe will reduce the pressure and therefore slow down the flowing current.

Note: It has been the case that I get asked if Betta fish need a filtering system quite often (more than I would like to admit). Betta fish produce waste and do need filtration.

Canister filters still hold the #1 place when it comes to maintaining decent water conditions.

If you’re planning on getting one, use a spray bar as an outlet.

These filters provide a strong flow rate, which needs to be spread out when dealing with long-finned fish. Browse some options and mind that you should not use them in aquariums with less volume than 10 US gallons.

6. Water is too cold.

Naturally, as with any other cold-blooded creature, a Betta won’t tolerate cold water.

They are tropical fish and thrive in waters with a temperature of 75 to 82 degrees Fahrenheit (24 to 28 in Celcius).

When the water is too cold, their metabolism gradually slows down.

This causes them to become lethargic and spend a lot of time at the bottom of an aquarium.

Slowly raise the temperature if you think this may be the problem. If by any chance the aquarium does not have a heater do some quick research on the best heaters for tanks that hold between 3 and 10 gallons of water and get one as soon as possible.

7. Its water too hot.

In summer an aquarium can get really hot.

Warm water releases oxygen too quickly which may leave your Betta gasping on the bottom.

Though Betta fish possess a special organ called Labyrinth, allowing them to breathe atmospheric air, they still may die if the water is poorly oxygenated.

In this case, you have to lower the temperature and add some extra oxygen to the tank:

  1. Lowering the temperature – DON’T use ice packs or ice cubes in the water.

    The sudden temperature change will stress both your pet fish and the good bacteria in the aquarium and, perhaps, even kill them. What you can do is place a fan to blow directly on your aquarium’s water surface.

    Another (obvious) solution would be air-conditioning the room.

    You could also eliminate any direct sunlight reaching the aquarium.

    Don’t keep the fish tank lights on for over 6 hours, which should be more than enough for your aquatic plants to grow. Note that LED lights emit little to no heat, so get one of those if you have the chance (hint: the link will help you with that).

  2. Oxygenating – Use a small air pump to help with bringing more oxygen to the fish tank.

8. Old Age.

Close up of an old Betta fish

by Catharsistar

Betta fish can live a happy and healthy life for about 4 to 5 years with good care.

Some may live even longer, but after hitting the 5-year mark they will become lethargic and more susceptible to disease.

Older Betta fish won’t have that youngster energy to explore.

They will prefer laying around on leaves or the bottom of your fish tank. If the lethargic behavior of your betta is coupled with heavy breathing, lack of appetite, or body swelling, it may be time to consult a vet. The combination of these signs can often indicate a betta is about to die.

9. High ammonia levels.

If your betta is breathing heavily while laying on the bottom then the fish tank may have an ammonia issue.

Ammonia spikes can be quite deadly to aquarium fish, so you need to confirm this as soon as possible.

Confirming an Ammonia poisoning is really simple – test your fish tank’s water. An excellent way to consistently monitor the ammonia in a fish tank is using Seachem’s Ammonia Alert sensor.

It accurately tracks ammonia levels continuously and it lasts for almost a year, which is impressive, given that it only costs around $7.

Finding the roots of the problem, however, can be more complex.

A couple of reasons for high ammonia may be:

  • An overstocked tank – the fish produce too much waste for the beneficial bacteria to handle.
  • Overfeeding – this is so because food waste turns into Ammonia.

    Monitor how much your betta actually consumes and offer less food than it can eat in one feeding session. Also, research how much and how often you should feed your fish for optimal long-term results.

    A good prevention of overfeeding is getting an automatic feeder.

    It will feed the fish just the right amount, even when you’re out of town. I can recommend this one on Amazon, as it’s an Eheim and it seems to work consistently.

  • Incomplete tank cycling – you’ve added the Betta before the aquarium was ready to harbor live fish. Tank cycling is when you leave the beneficial bacteria enough time to develop a colony in their new tank. In return, they will transform the dangerous ammonia levels into way less harmful Nitrates and your new pet fish won’t be in danger.

    A fully cycled fish tank shows readings of 0 ppm of Ammonia, 0 ppm of Nitrite, and 10 or more ppm of Nitrate.

    Full, natural cycling takes no less than a month. You can speed that process up to just about 2 weeks if you’re using bottled bacteria to kick start the Nitrogen cycle (learn more about that by clicking the link to see the guide I wrote).

The good news here is that you can almost always fix high ammonia levels by doing water changes. Your initial water change should be no more than 50%.

Dechlorinate the new water before putting it in the tank by using a water conditioner such as Seachem’s Prime and continue to perform a 20% water change every week.

10. Stress or Disease.

There are a number of diseases that put a fish on the bottom of its tank.

Due to the way, betta fish are bred their immune systems are weaker than most fishes’ by definition.

If you still haven’t found the solution to your problem then I have bad news for you.

Pay attention whether the hanging out at the bottom is combined with atypical behavior, weird white spots appearing on your betta’s body, loss of coloration, cloudy eyes, inflamed fin patches, etc.

If any of those is true then your betta is probably sick and you should be concerned. All of these symptoms indicate something more than a lazy personality.

Stressed Betta fish with frayed fins and discolored body

by wilddogslushie

If it’s a female betta with a swollen belly and you’ve concluded it’s not constipation then it may mean that the fish is eggbound.

Sometimes this condition sorts itself out, but not every time.

If that’s the case, then little can be done. Note that this is just one of the reasons for a bloat in Betta fish.

Anyway, if you suspect an infection then treating with Epsom salts can be beneficial.

You can also let some Indian Almond leaves sit in the water.

They will release tannins, which help with infections and strengthen the immune system of your fish.

However, the best thing to do if your fish seems like it’s about to perish is to make sure your tank’s water parameters are in check. A stress-free environment for your betta can also make the difference.

One quick yet absurdly efficient way to reduce stress levels in betta tanks is by adding up some live plants.

These will artificially recreate the betta’s natural environment which may be a significant help in keeping stress at bay.

I recommend the addition of surface water plants that remain afloat if you think your betta may be stressed out. They filter the aquarium water from excessive organics, provide interesting surroundings for exploration, and also get as close to the betta’s native rice paddies as possible.

Oh, and they look great.

11. Its Aquarium is too small and the fish feels confined.

A blue betta swimming in a heavily planted tank

by Razzyxcxc

Although Bettas are among the smallest fish in the hobby keeping yours in anything under a 3-gallon tank may mean it’s time for a change.

The size of a 3-gallon tank is the BARE MINIMUM for a Betta fish. Ideally, you’d keep this fish species in a 5 or 10-gallon tank to allow for more free roaming. An argument to upgrade would be that smaller tanks are very difficult to keep in check.

Each small change in the water’s parameters can immediately throw the whole system off balance and your Betta will have nowhere to retreat to.

“Dilution is the solution to pollution.”

Anyway, another point I’d like to make is that, as mentioned above, Betta fish are curious, and also like their private space.

When the aquarium is too small and there’s no space to explore or retreat to, the stress may start to show.

Your betta will lose its life spark and it may prefer to do nothing but stay on the bottom.

Remember that in their natural habitat betta fish have a ton of horizontal space to swim in.

They are found in rice paddies and though shallow, these always provide more room to discover or a good hideout.

So, in case your betta tank is no more than 2-gallons in volume I would strongly suggest that you consider getting it a larger home.

Make sure the new place has LOTS of plants as well. I can help with choosing the right aquarium with this guide.

Good luck. The larger tanks also give the opportunity to house more than just a betta.

12. Sudden shift in water parameters after a water change.

Despite our best intentions, we sometimes end up doing more harm than good to our aquatic pets.

This often happens when we neglect a small detail in a simple routine we’ve done millions of times before.

Since water changes are one of the most frequent maintenance routines, we often tend to gloss over them.

Such missteps on our part, however, can seriously affect the health of betta fish and put them at the bottom of our tanks.

Apart from the temperature fluctuations I’ve pointed out, a water change may also sink a betta by altering water chemistry. This mostly happens because of osmotic shock.

If you perform a large water change in a fish tank with elevated levels of nitrate, you run the risk of sending your fish into osmotic shock.

Even though nitrate buildup can poison fish, most species can tolerate certain amounts of it.

When fish adapt to the increased nitrate levels, their bodies start retaining a higher amount of (NO₃-) ions.

The amount they retain, however, isn’t equal to that of the surrounding water.

As a result of this polarity, the surrounding water tries to suck out the nitrate ions from the fish’s body through osmotic pressure.

Fortunately for betta fish, mother nature loves balance so it protects them through a process called osmoregulation.

The powers of osmoregulation, however, aren’t unlimited.

In a polluted tank, the sudden shift in nitrate levels is so big that it overpowers the fish’s osmoregulation and sucks out its nitrate ions.

Apart from the bloating that may be observed, this stresses out the betta and may lead to unusual behaviors such as sitting at the bottom of the tank.

Related Read: Why Do Fish Die or Get Stressed After a Water Change?

My Conclusion

betta fish at bottom of tank header

To witness a betta peacefully laying at a fish tank’s bottom is not uncommon.

It’s all about knowing your fish and its habits.

Carefully monitor its behavior and conclude whether it’s just a way of living or an issue in disguise.

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Momchil

Momchil Boyanov is the Founder and now Senior Editor of AquAnswers. He has over 13+ years of experience in keeping home aquariums as well as providing professional aquarium services. Momchil has had his fair share of adventures in aquarium care. He has made MANY mistakes throughout his fishkeeping journey and thus learned A LOT. Through Aquanswers, Momchil shares knowledge about freshwater and saltwater aquariums with the people within this community.

88 thoughts on “Betta fish Laying at the Bottom of the Tank: 12 Reasons Why”

  1. My Betta has recently been only sitting at the bottom of the tank and breathing heavily. I don’t know how long they’ve been breathing like that (I only new from this mornings interaction) but they’ve been sitting at the bottom for the past week. I really don’t wanna stress them out anymore than they are, and I’m planning on going out and buying them a new tank, so I’m wondering how I can make it less stressful for them?

    I know new surroundings might be much, and I’m not sure if it’s a bladder infection so I’m scared to make the water too high.

    Normally they’d flare at me for like, five minutes until they’d follow my finger around but now their personality is really dull and I don’t want to accidentally kill them or harm them in any way.
    Their color is a bit dull as well, I’m not sure what else to do.

    I’m also not sure how to check if the acidity is too high or low,
    And if the tank is too hot since it is summer. (Although my room is conditioned nicely so I don’t think it’s that)

    Should I leave my tank half full Incase they are having air problems? They don’t seem to move much and if it’s pain or discomfort I want to dull down the amount of it they feel until I can adjust their surroundings accordingly to help them feel more at ease.

    Sorry for the confusing questions, but if you ever have time to reach back I’d appreciate the help.

    • Hi Danielle,

      How big is the tank? Leaving it half-full means 50% less water, and small amounts of water can result in dangerous fluctuations in parameters and less time to deal with them (read the smaller the tank, the harder it is to maintain stable water parameters).

      You should probably invest in a thermometer for the water and provide it with some water movement (you can either blow a fan on the surface, or get an aerator, or position the filter you currently have to “splash” more on the surface, as I’m assuming it’s a HOB). This will oxygenate the water more.

      Bettas are super happy when there are plants around them. I’ve shown how a good betta tank should look on a photo in this article: https://aquanswers.com/best-betta-fish-tank-kit-novice-friendly-size-and-filter/

      Do you have a test kit? You probably don’t. It’s used to measure ammonia (bad), nitrite (also bad), nitrates (harmless if below 25-30 ppm). There are also ones that measure water pH (acidity). The higher the number the less acidity (anything above 7 is considered alkaline).

      If the betta is not swimming sideways or belly-up, then it’s not a swim bladder infection.

      Paleness COULD indicate a fungal infection (which may be a result of poor water quality, say, too much nitrAte).

      And then, there’s stress. Flaring does mean the fish gets emotional. Keeping bettas together could also be stressful for them as they are a bit territorial. Stress could also be a result of the poor environment (small or poorly decorated tank).

      In any case… Changing to a bigger tank with more plants could mean an improvement unless you’re dealing with a fungal infection. The latter should be treated separately but could also be avoided in larger tanks, because the water parameters are WAY more stable and provide a healthy environment for the fish to develop a strong immune response etc.

      Makes sense?

      Hope this was of help.

      Good luck with the little guys.

  2. just please help i dont know what to do

    • Hi Alpine,

      How big is the tank? If below 3 gallons it’s too small.

      In case your dad does not allow you to change that you can try to get your buddy more live plants which will keep a more healthy environment by absorbing nitrates (which is important in smaller tanks) and will also provide more hiding places so the fish does not feel as stressed.

      Plants also provide more oxygen during the daytime, which in smaller tanks is essential (judging from your little guy’s behavior).

      Bettas require higher water temperature which means even less oxygen (warm water releases dissolved oxygen quicker).

      tl;dr – If you can’t get a larger tank, try introducing more plants.

      Hope this helps, Alpine!

      • my dad says we can get him more live plants but its a maybe on the bigger tanks

        • Happy to hear that!

          Hope he gets better!

          • my dad has been giving him bettafix even though he doesnt have fin rot he has been getting alot more active

          • That’s great to hear! (and confusing) 😀

  3. he has a hiding spot maybe he needs more live plants

  4. and his tail sometimes droops down

  5. i think my betta might be sick i told my dad we should get him a bigger tank but he said no he some times droops over on his
    side but some times hes active and swims to the top to see if theres food and sometimes he just sits there

  6. I got my betta yesterday from petsmart checked his water and it was in danger of ammonia. I acclimated him. Now he is nose diving towards the bottom of tank around plants by filter. Is it cause he’s getting used to the new tank or sick

    • Hi Courtney,

      Nose-diving sounds like he’s exploring his new tank. Did you handle the ammonia readings in time?

  7. Hi my Betta Moo is starting to worry me he started by hiding behind the filter and so I decided to take it out and everything was good until I realized he was like hiding in corners so I thought my room must be to cold and so I relocated him to the living room and I realized he isn’t eating he isn’t swimming he is just floating around and laying on his side at the bottom and top of the tank please someone respond I’m very nervous

    • Hi Nicole,

      Not eating is a serious condition.

      He seems utterly stressed.

      Were the places where he hides avoiding filter current? He may have been too tired of swimming with a current (corners, behind the filter’s current). Put a sponge or filter floss on the outtake.

      This is my best guess without seeing all of it.

      Hope this helps!

  8. I just got a female betta, Pepper, today, and I put her in my 5 gallon tank with my male, Stark. (Yes, I did name them after the MCU characters) Pepper has been spending most of her time in the corners at the bottom of the tank. She’s definitely eggbound, as I’ve encountered it before so I do know only a little, but her breathing seems very labored. She and Stark haven’t had many problems, he’s flared up a few times, but nothing too serious. I’m not sure what’s going on with her. I just set the tank up today, so maybe she’s getting used to it??? But the heavy breathing is new to me… help please!

    • Hi Lauren,

      1. Check if the nitrogen cycle is stable. Introducing new fish in a small tank does mean more waste.
      2. Get a fan to blow on the water surface. Agitation will increase oxygenation. Do you have an airstone?

      Also very brave move to house them together. Hope this works out! : )

  9. My beta fish is laying on his side and if i move the tank he like freaks out in little spins and then just stops suddenly and lays bck to the bottom what is wrong with him!?

  10. What happens when your betta can’t swim up to the food and it’s a one gallon tank

    • Hi Brock.

      In that case, you begin the search for a larger tank…

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