Do Fish Sleep on The Bottom of The Tank

Fish in your Aquarium are hard to figure out sometimes. If the tank is not right, the fish could be stressed, sick, or worse, and can be found on the bottom of the tank.  Do Fish sleep on the bottom of the tank or are they sick?

Yes, Most fish sleep just off the bottom of the tank, floating and moving slightly in an upright position, 9-12 hrs. per day. Sometimes a pair or group close to the structures or plants in the tank provides some security from unknown dangers. 

There has to be some sleep time, for fish in your aquarium and since they don’t close their eyes and lay down it’s a little difficult to know when they do it. They also hang on the bottom when they’re stressed and sick, it’s good to know the difference between when a fish is having a good night’s sleep and is stressed and diseased. Here are some ways you can tell.


In the watery depths of our home aquariums, a curious observer might wonder about the nocturnal habits of our finned friends. Do fish partake in the same slumber rituals as land dwellers, or do they have their own unique underwater bedtime practices? Particularly intriguing is the question: “Do Fish Sleep on the Bottom of the Tank?” This aquatic mystery invites us into the fascinating world of ichthyology to unveil the secrets of piscine rest. Join us as we dive beneath the surface to explore the somnolent behaviors of these silent swimmers.

Do Fish Sleep on The Bottom of The Tank


Just like humans, fish require time to sleep. The best time and the most natural time for them to sleep is when the lights are out in the aquarium. They will tend to hover in one place in a trance way that appears differently than they normally do. As the owner of the aquarium, you need to mimic a natural existence by turning off the light at the same time every night.

Do Betta Fish Sleep? How, When & Why They Rest (Explained)This will provide them a night and day scheduled clock, almost what they would experience in a natural environment where they can wind down and then fall asleep.

Most Fish need to move to breathe, so even though they are sleeping, they will move slowly pulling water through their gills to provide oxygen to their bodies.

Others have an adaptation called spiracles that force water past the gills and allow the fish to stop swimming for a good night’s sleep. Fish will sleep between 9-12 hours a night normally near or at the bottom of the tank.

Some will move their tail to keep oxygen moving through their gills but it’s pretty easy to tell the difference between a fish that is stressed and a fish that is tired and trying to snooze if you examine them and know their routine.

A fish sleeping in your aquarium will remain upright on the bottom of your tank at the same time or near the same time at night. It will find a safe place in between rocks, plants, or some kind of structure until he wakes and is refreshed. Some fish may burrow themselves in sand or pebbles at the bottom of the tank.

Some fish, like the Parrotfish, will excrete mucus to surround themselves as they rest. In most stages of rest, a fish will wake up at the slightest sound or if the aquarium lights go on. It’s just a matter of survival.

In the real world of fish, a shark can sleep so sound, at night in the ocean, that oceanographers can lift the shark up and out of the water without waking it. The shark isn’t worried about any fish gobbling him up.

Some fish will float an inch or so off the bottom others will lay on the gravel at the bottom with other fish who keep them off the menu of a predator fish. They will sleep together paired off with a buddy in between objects in the aquarium that can act as cover for them.

Most people who own aquariums believe that fish like other pets will sleep when you sleep and get up when you get up. Turning the light off settles them down and helps them go night-night.

So even though they are not closing their eyelids and laying down flat, they’ll have a period when activity and metabolism slow way down as a way to conserve energy and restore the energy levels in their body just like any creature on earth.

Concerning Causes of a Fish Laying at the Bottom of the Tank


A fish lying at the bottom of the tank can be indicative of various health issues or environmental factors. Here are some potential causes:

  1. Water Quality Issues:
    • Poor water parameters, such as high levels of ammonia, nitrites, or nitrates.
    • Incorrect pH levels or water hardness.
    • Lack of oxygen in the water.
  2. Temperature Fluctuations:
    • Drastic changes in water temperature can stress fish and lead to health problems.
  3. Disease or Parasites:
    • Bacterial, viral, or fungal infections.
    • Presence of parasites like ich or flukes.
  4. Stress:
    • Overcrowding in the tank.
    • Aggressive tank mates.
    • Sudden changes in the environment.
  5. Poor Diet:
    • Inadequate or improper nutrition can weaken a fish’s immune system.
  6. Old Age:
    • Some fish may naturally become less active and rest at the bottom as they age.
  7. Injury or Trauma:
    • Physical injuries from tank decorations or aggressive tank mates.
  8. Environmental Factors:
    • Inadequate hiding places or lack of suitable hiding spots.
    • Insufficient lighting.
  9. Digestive Issues:
    • Constipation or other digestive problems can affect a fish’s buoyancy.

If you notice a fish lying at the bottom, it’s crucial to assess and address these potential issues promptly. Regular water testing, maintaining proper water conditions, and observing fish behavior can help prevent and manage such situations. If you’re unsure, consulting with a vet or a knowledgeable aquarium professional is recommended.


Why Did My Goldfish Change Color

Is It Normal for a Fish to Lie on The Bottom of The Tank


No, it is not normal for a fish to consistently lie on the bottom of the tank. This behavior often indicates an underlying health issue or environmental problem. It is crucial to monitor water parameters, assess the fish’s overall condition, and address any potential causes, such as poor water quality, disease, or stress, to ensure the well-being of the fish.

So for some fish to get some rest, fish need to find a place at the bottom of the aquarium to nettle in and get some quality time. It’s quite normal for you to see your fish nettled between some plant and hunkered in for the night. The problem is when to recognize that it’s not normal and the fish is acting strangely, especially at the bottom of the aquarium.

You need to know the difference between a fish that is sleeping and a fish that is stressed. Pay attention to your fish and they will show you what they need to know. Do your water testing, know what the parameters are, and what important role they play in the role of the aquarium’s ecosystem. You can find anything for your Aquarium system right here on  

This site can give you the information you need for a successful aquarium along with testing equipment like digital meters that can keep you a step ahead of your Aquarium. If you are busy and need an easy way to monitor try an Electronic tester like this that is reliable and easy to use Bluelab MONGUA Guardian Monitor for pH, Temperature, and Conductivity Measures, Easy Calibration, and wall-mounted 


A  fish that is Stressed at The Bottom of the Tank                          

  • Is the fish lying on his side? Fish will keep themselves upright, balanced, and in place slowly moving their fins. These motions will not give them any focused directional movement. You will probably notice that your fish has a droopy tail, as well.
  • Decreased activity of the mouth: Fish won’t move their mouth while they are sleeping.
  • How long has the fish been laying on the bottom? Normally fish will sleep 9 to 12 hours and will wake up with aquarium light or noise. Drop a flake of food next to the fish and the fish won’t respond.
  • If you have a fish in your freshwater aquarium that appears to be sleeping on his side or on his back, a serious ailment known as swim bladder disease is the culprit.
  • if the fish is lying on the bottom of the tank and his gills have a reddish or purplish look or the fins appear to be streaked with red — your tank may have a high ammonia content. Or an Oxegen content where the fish is looking for more at the bottom.
  • Check parameters for the aquarium, PH, Nitrates, ammonia, Oxygen, and temperatures.


A fish that is Sleeping on the Bottom of the Tank 

  • A fish that is sleeping will have a subtle loss of color that will return to normal after it awakens.
  • Fish will likely doze off at the same time every day. That time could be brought on when the lights are turned back off giving him the sense of day and night.
  • Fish do show some signs of being asleep like being unaware of their surroundings, bumping into things in the tank, slowed fin and tail movements, less frequent body movements, and becoming inactive around the same time every day or night.
  •  If the fish is sleeping will show no signs of sickness or death which could be sunken eyes or a bloated body.
  • A fish that is sleeping at the bottom of the tank will have no movement in their mouth.
  • The fish could be exhausted if you leave lights on and the fish can’t sleep and show signs of exhaustion. They aren’t sick but will get sick. Shut out the lights and see if it makes a difference.
  • Try and net the fish, a sleeping fish will awaken and struggle no matter how sound asleep he is.
  • Check for movement it’s moving it’s breathing.


Proper pH For Freshwater Aquarium

Diseases that Encourage Fish to Stick to The Tank’s Bottom


A sick fish can look like he is sleeping. If you have determined your fish is still alive but very sick, research his symptoms to see if medicating with drops first, might help him or a water change may help. If you choose to end his suffering, you can euthanize him with clove oil.

Separate the fish into a breeding/separate tank and add about 400mg of clove oil to one liter of water. The clove oil will cause the fish to lose oxygen, and he will pass away peacefully. This method is far more acceptable than flushing your finned friend fish in the toilet bowl.

Fish sticking to the tank’s bottom could be a sign of various diseases or health issues. Here are some diseases that may cause this behavior:


Check all your equipment like thermometers and heaters and all your parameters test Ammonia, Nitrates Oxygen, and pH. Check all inhabitants of the Tank and make sure they coexist together, Include the fish and the plants too. Make sure you are not overfeeding the fish which can lead to Swim Bladder Disease when a fish eats too much and gulps air or is in water that’s too cold.

A sick fish may have spots. Check for color changes, patches, or a slime coat. Most conditions can be cured with an additive or some specific medications.

Balance dark and light, In the same way, they would experience in the wild. Some fish are nocturnal, meaning they are active at night, while others are diurnal, meaning more active during the day. Both types of fish will require a good balance of light and dark to sleep and function as naturally as they can.

Make sure the fish isn’t experiencing an external source of stress or an internal source of stress. You can experiment with a few different explanations of what may or may not be happening except for a few fish.

Most fish sleep on the bottom of an aquarium with a buddy or two, where the structures provide some security from any unknown dangers. Know what Aquarium’s water chemistry is and how to change things when they’re not. Remember to shut out the lights every night to give your fish a sense of day and night. Sometimes the best medicine is just a good night’s sleep. Never touch a fish’s gills, they are extremely delicate, and just touching them can damage them. Never lift a fish out of the water by holding the belly area.


In the still depths of aquariums, fish do curl into a state of rest akin to slumber, but not precisely as we experience it. With no eyelids to bid the world goodnight, they enter a phase of lowered activity and metabolism, which can occur at any tank layer, including the bottom. As we delve into the piscine dreamscape, we recognize that sleep manifests in myriad forms across the animal kingdom. So, the next time you find your finned friends listlessly lounging or suspended in stasis at the base of their aquatic abode, you might just be witnessing their version of counting sheep beneath the waves.


JimGalloway Author/Editor


Aqueon- Fish Sleeping Habits

Hartz- Fish Behavior Basics



Q: Can my fish tank’s setup influence where my fish sleep?
A: Absolutely! A comfortable substrate, the presence of plants, clean and appropriately-temperature water, and a consistent light cycle all contribute to creating a suitable environment for fish to sleep, whether at the bottom or elsewhere.
Q: Are there specific reasons why a fish would choose to sleep at the bottom of the tank?
A: It can be a matter of species-specific behavior, a search for a dim or secure area, or even a comforting spot among tank decorations. Some fish, like bettas, often sleep at the bottom out of habit and preference.
Q: How can I tell if my fish is sleeping or if there’s something wrong?
A: Look for changes in usual behavior, check for other symptoms of stress or illness, and ensure the tank’s living conditions are well-maintained. Observing your fish’s active behavior can also help determine if bottom-sleeping is normal for them.
Q: Do all fish sleep the same way?
A: No, fish sleeping habits can vary significantly between species. While some might prefer the tank’s bottom, others engage in slumber while floating or hidden in the foliage. Each species may have unique resting patterns adapted to their lifestyle.
Q: What should I do if I’m worried about my fish’s sleeping behavior?
A: Monitor the fish for any additional signs of illness or stress, check water conditions and quality, and consider whether any environmental stressors could be affecting your fish. If needed, consult a veterinarian specializing in fish.


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