There is nothing worse than noticing that your pet fish is laying on the bottom of the tank and not moving and we constantly see people reaching out and asking why their fish is laying on the bottom of the tank.
Due to this, we have decided to publish our own article going over the four most common causes of a fish laying at the bottom of its tank in the hope that we will be able to help as many of our readers as possible identify the issue with their fish and correct it.
Thankfully, the majority of the reasons that may cause your fish to act in this way are relatively easy to treat provided that you catch the condition early enough.
That said, if you have noticed that your fish has been acting in this way for a few weeks without being able to treat it or if your have started treatment but your fish is not responsive then seeking advice from a vet is the best route to take.
They will be able to offer you specific advice on the condition of your fish and exactly how you should be treating it.
Although the four main problems that result in a fish laying on the bottom of their tank are usually easy to identify, if there are multiple issues at play then you may only be treating one cause while the other is left to develop.
Why Do Fish Lay At The Bottom Of The Tank?
The main four reasons that fish will lay at the bottom of their tank are due to swim bladder disease, white spot disease, ammonia poisoning, and injury. If your fish is old and is close to death then this may also cause your fish to lay on the bottom of its tank too.
Some fish that are being bullied by other fish in the tank will also start to stay close to the bottom of the tank as possible but not quite lay on the substrate.
This is generally due to trying to find cover and protection from the other fish in the tank so adding something for the fish to hide amongst may stop this but it may need to be put in a separate tank.
Although this may sound obvious to some of our readers, we get a large number of beginners asking about their bottom-dweller laying on the bottom of their tank constantly.
If you have noticed this behaviour in a bottom dweller such as a cory or a loach, this is totally normal for that type of fish and is generally not something you have to worry about.
How Can I Help A Fish Laying On The Bottom Of The Tank?
There are over the counter treatments available for swim bladder disease, white spot disease, and ammonia poisoning that can make it very easy to treat the issue that is causing your pet fish to lay on the bottom of its aquarium.
If your fish is staying at the bottom of its tank due to injury then in time it may heal mild injuries itself.
If you are able to see obvious injuries from other fish being aggressive to your fish, we would usually recommend that you place it in a quarantine tank until it has had a chance to heal.
While the fish is injured it will be even weaker than usual making it more vulnerable to the fish that attacked it.
In the vast majority of cases though, you really should be trying to move any fish that lays on the bottom of its tank to a quarantine tank.
This helps to prevent any potential illness in the fish from spreading to the other fish in the aquarium and steps should usually be taken to clean the water in the main aquarium as well as treat the other fish with a lower dose to prevent the same issue breaking out in them.
Swim Bladder Disease
Swim bladder disease is probably the most common cause of a fish laying on the bottom of its tank without moving.
Both are very beginner-friendly with dosing instructions on the labels of the product on how you should use them relative to the size of your aquarium.
White Spot Disease
White spot disease is probably the second most common reason that an otherwise healthy fish would lay on the bottom of its tank and not move.
If you catch white spot disease early enough then you are usually able to treat it quickly with API Super Cure.
If the white spot disease has set in on your fish then it can be more problematic to fix at home and seeking assistance from a veterinarian or a more experienced fish keeper is recommended.
Ammonia poisoning can be more common with beginner fish keepers and will cause some fish, especially the more sensitive species to lay on the bottom of their aquarium.
A water test kit will be able to give you a better idea of what’s going on in your tank as you also have to factor in the pH of the tank too.
You are able to try ammonia detoxifier but this is one of the more problematic causes to fix yourself, especially if you are new to fish keeping.
Some fish will end up fishing each other and ending up injured and some injuries can cause your fish to lay at the bottom of its aquarium while it heals.
There is such a wide range of potential injuries that can occur to your fish that it is very difficult to work out exactly what may have happened.
Sharing photographs of the injuries on social media in fish keeping groups can be a good route to take to try and work out exactly what is happening and your fishes chances of survival.
Is A Fish Sitting At The Bottom Of The Tank Dying?
Not all fish sitting at the bottom of the tank are dying or will die soon. Most of the common causes of a fish laying at the bottom of its tank are actually surprisingly easy to fix in most cases, even for a beginner.
This allows you to easily treat the issue with your fish and help your fish back to full health as quickly as possible.
A small number of fish species my actually lay at the bottom of their aquariums during mating season simply due to being tired from chasing each other around the aquarium too.
This tends to only last for a few days to a few weeks at a time depending on the fish species and you can usually see the higher levels of activity in the fish to help you diagnose the cause.
Unfortunately, though, some fish who are about to die naturally will lay at the bottom of their tanks due to a lack of energy.
Some of the fish that do end up with swim bladder disease, white spot disease, and ammonia poisoning may also end up dying too if the condition is serious enough.
Is A Fish At The Bottom Of The Tank Just Resting?
Some fish species will exert so much energy during their chasing games during the mating season that they can end up laying on the bottom of their tank just to take a rest.
You will usually be able to see much higher activity levels in your fish during this time period making it easy to understand.
If some of the fish in your aquarium are also competing to be recognised as the dominant fish then they will also exert higher than average levels of energy too. This can cause them to lay on the bottom of the tank while recuperating their energy.
Fish species such as betta fish also like to have a leaf hammock in their tank for them to rest on too. If they have no leaf hammock available then they may end up resting on the bottom of their tank by laying on the substrate.
Fish At Bottom Of The Tank And Not Moving After A Water Change
It can be common for some sensitive fish species to lay at the bottom of their tank after a water change due to going into thermal shock.
This is caused by the temperature of the aquarium changing by a few degrees as you add the new water to the tank. As the water heats up to the normal temperature then your fish should return to normal.
Depending on the severity of the temperature change and how sensitive your fish is, thermal shock can actually kill some fish species.
The majority of the time, thermal shock is also very easy to avoid by taking a few simple steps. The first is to try and heat the new water up to the same temperature of your main aquarium but we understand not everyone is able to do this.
The easiest method and the one that we would recommend that our readers take advantage of is to just add small amounts of the new water to your aquarium at a time.
This does stretch the process out but the smaller amounts of water, maybe even as small as a single glass of water will usually not have as much of an effect on the water temperature in your tank.
Do Fish Sleep At The Bottom Of The Tank?
Some fish do sleep at the bottom of their tank and this can be a common reason that your fish may lay on the substrate for a long period of time. Other fish try to sleep on the leaves of the plants in your aquarium so you may see fish laying on leaves at times too.
There are a number of factors that come into play about the sleeping habits of your fish though so it is not as easy as saying that your fish is laying on the bottom of its tank due to needing to sleep.
If your fish does sleep at the bottom of the tank then once it wakes up, a healthy fish will return to normal behaviour of swimming around as it usually would.
This can be one way for you to try and rule out if your fish is at the bottom of your tank simply due to sleeping or if it is due to illness.
If the fish is on the bottom of your tank enough for you to notice then it is probably due to an illness or injury though rather than being due to wanting to sleep.
Why Is My Fish Laying On The Bottom Of The Tank Breathing Heavy?
The most common reasons that your fish may be laying on the bottom of your tank and breathing heavy is due to ammonia poisoning, nitrate poisoning, or hot water temperatures.
All three are easy to fix in most cases and once the issue has been corrected, your fish will usually return to normal.
This is why you really need a water test kit, even as a beginner as it lets you keep tabs on the ammonia and nitrate levels in your tank to give you an early warning for any potential problems.
It can be good to get some specific guidance for your specific situation in these cases from a more experienced fish keeper though.
If the issue is the water temperature then adjusting the temperature as required will often be able to fix the problem.
Why Is My Fish Lying On Its Side At The Bottom Of The Tank?
The two main reasons that your fish may lay at the bottom of its aquarium on its side is due to swim bladder disease or due to the water temperature being too hot or cold.
Both of these are relatively easy to fix in most cases allowing you to get your fish back to normal quickly.
If your aquarium is too hot or too cold for the particular fish species that is laying on the bottom of the tank then this is probably the issue.
Even a few degrees can be enough to cause your fish to act like this, especially in the more sensitive fish species. Adjusting the temperature of your tanks water will usually be enough to have your fish back to normal within a few hours.
Most of the time, they will be enough to treat the issue and have your fish back to normal in a week or two.
That brings our article going over why your fish is laying on the bottom of your tank and how to fix it to an end. Unlike some of the other common issues that we see people reaching out and asking for advice on, a fish staying at the bottom of the tank is usually much easier to fix than most people realize.