Where Do Mollies Swim in the Tank (7 Sick Fish Signs & Cure)

Mollies are freshwater fish that many aquarium hobbyists choose to have in their home tanks. But do you ever find yourself wondering, where do mollies swim in the tank?

Or you may have noticed signs that your molly is sick, but you don’t know what to do about it or if there’s a cure. Fear not!

In this post, we will cover everything from typical swimming patterns and hiding behaviors of mollies to seven possible signs that may indicate sickness, as well as effective molly fish care techniques and suggestions for remedies.

Balloon molly fish

Whether you’re an experienced aquarist or just starting with keeping tropical fish healthy at home – stay tuned because, by the end of this article, you should quickly tell whether your pet molly is feeling fine or has taken ill.

Are Molly Fish Very Active?

Mollies bring a splash of vibrant activity to any aquarium, but their curious nature can disrupt the peace if placed with slow-moving companions.

Their occasional nibbling habits make them less than ideal tank mates for long-finned fish that need to keep up with their active lifestyle.

Mollies are active fish that love exploring their environment and feeding on whatever they can find.

The most common swimming pattern is steady cruising around the tank as they inspect every corner of their habitat.

It is often accompanied by fanning behavior in which they spread out their fins to collect food particles floating in the current.

Where Do Mollies Swim in the Tank?

Mollies prefer the higher waters, rarely straying far from their aquascape’s middle and upper fish tank areas. 

Keeping them out of deeper seas ensures these little swimmers remain safe and sound inside your tank!

In an ideal tank, mollies swim around the perimeter of the aquarium, paying particular attention to hiding spots and any live plants or other decorations they can use for shelter from strong currents.

They prefer well-oxygenated water (pH levels between 7.5 to 8.5) with plenty of space to explore and forage for food.

7 Sick Fish Signs of Illness to Look Out For

Unfortunately, molly is sometimes sick molly. Mollies have not been described in this article before, but they do not eat loaches, and other mollusks like loaches if they are.

If your fish does not have a pregnancy, you must first see any signs of common fish diseases.

Here are some health conditions that should be checked:

1) No Appetite – If you notice that your molly has stopped eating, it may indicate stress or a more serious underlying health issue. To boost your molly’s appetite, check the water parameters, ensure it is eating the right food, and provide a good hiding spot.

2) Changes in Color – If your molly’s color appears dull or faded, it could indicate a disease or parasite. Look for signs of Ich (white spots on the molly’s body) or velvet (a rash-like appearance). Treat with medication as soon as possible.

3) Clamped Fins – If your molly’s fins appear clamped shut, this could be due to the low water quality or temperature. Check the tank parameters and ensure they are within optimal range before treating them further.

4) Swimming Erratically – Erratic swimming behavior, such as swimming upside down or darting around the tank, could be a sign of disease. Check for signs of parasites and treat accordingly.

5) Spots on Skin – If you notice spots on your molly’s body, it could indicate an infection, such as bacterial or fungal infection. Treat with appropriate medication and create a healthy environment by checking water parameters regularly.

6) Weight Loss – If your molly appears to be losing weight, this could be due to starvation or poor food quality. Ensure that you are providing your molly with high-quality food, and check for any signs of parasites or diseases in the tank.

7) Bloating – Several things, including poor water quality, diet, or parasites, can cause a bloated molly. Check for signs of disease and treat accordingly before feeding your molly with a small amount of ‘bloat’ food or medication.

By understanding the symptoms of common molly illnesses and taking simple steps to maintain optimal conditions in their tank, you can easily ensure that your mollies stay healthy!

If you notice any changes in your fish’s behavior or appearance, it is essential to act quickly and provide the necessary treatment.

With a bit of attention and care, these happy swimmers will remain part of your household aquarium for years to come!

3 Reasons Why do Mollies Stay at the Top of the Tank

Mollies are little tropical fish but active. They will have plenty of room for exploration. If a man spends too much time on the top of the tank, he will be responsible for the following:

Your Molly isn’t Happy in its Tank

Sometimes, the Mollies jump on the top and stay there because they lack oxygen. They often try to avoid lower-class conditions, such as a lack of oxygen or higher temperatures.

Usually, if you are providing the right soft water conditions, they will stay near the bottom.

But before that happens, they have trouble breathing. If you look carefully, the gills are inflamed.

The gasps for breath will be visible, which generally indicates the tank is devoid of oxygen. If it is a tank where oxygen has been checked, it must be checked for ammonia. Molly runs to the surface to ward off Ammonia nitrates and nitrites. They will remain on top until there is a solution.

The fish needs to get more oxygen.

When fish hang over their surface, they are immediately concerned to produce oxygen in the water. This happens because adult fish gills take oxygen from the seawater.

Naturally, oxygen evaporated in tanks by surface vaporization. In case of a drastic oxygen drop, the only rational solution is to rush into the water to rehydrate it and maintain a healthy oxygen level.

A molly fish with an oxygen shortage will also rapidly gasp and open its mouth. Molly may end up lazy because they need to swim more effectively.

Your molly is stressed.

Stress can force fish to perform unnatural actions. Then you either lay still under the tank or stay on top. Stress has a lot of causes, including lack of water conditions and bullies.

It is also worth mentioning that if you have recently placed your molly in the tank, it can take up to a few weeks to get used to the new environment. During this period, it may remain stuck at the top of the tank as it is trying to adjust.

Is It Normal for Mollies to Swim at Top of Tank?

Yes, it is normal for Mollies to stay at the top of the tank. This behavior can be attributed to their instincts, lack of oxygen in the tank, stress, or poor water conditions.

It is crucial to properly monitor and maintain the water parameters to ensure your Mollies stay healthy and happy!

If you notice any changes in the behavior of your hardy fish, it is vital to act quickly and provide the necessary treatment.

By understanding the symptoms of common molly illnesses and taking steps to maintain optimal conditions in their tank, you can easily ensure that your mollies stay healthy and happy.

How to Handle Mollies that always Swim at the top?

If your molly is always swimming at the top of the tank, it is essential to identify and address the molly fish lying cause. This may include checking the water for ammonia or oxygen levels, ensuring that the tank is not overcrowded, and providing adequate hiding spots, as well as

5 Ways to handle Mollies that Stay at the Top of the Tank

Regular Water Changes

A tank needs regular water changes. Molly fish typically needs 20% less water to be healthy and should be changed twice daily after taking any medication.

Adequate Hiding Spots

Mollies need plenty of hiding spots like plants, rocks, and caves. If these are not provided, they will not feel secure and may remain near the top of the tank.

Adding Oxygen to Your Tank

The oxygen level of the aquarium is raised in numerous ways, like increasing surface area, using an air pump, and adding plants. Producing oxygen to the tank is vital for mollies as they need enough oxygen to breathe and survive.

Checking for Ammonia Levels

It is essential to check your tank’s ammonia levels as this can be toxic to fish. If levels are high, it can lead to mollies swimming at the top of the tank.

Adjusting the Water for Mollies

Molly water tank is regularly changed. Only so can we stop concentrations of ammonia and other harmful chemicals. Nonetheless, water change doesn’t help. You need an efficient filter to eliminate water debris.

Why Is My Molly Fish Swimming in Place?

Molly fish may swim in place due to stress, illness, or poor water conditions. It is essential to check the water parameters and inspect the fish for signs of injury or disease.

When Molly Fish struggles with environmental stress, they may succumb to a peculiar behavior known as “Swimming in Place,” where the fish remain stationary despite their active movements.

If your molly is still displaying this behavior after correcting the environmental issues, it may need more time to adjust. It is also possible that your molly suffers from an underlying health issue, so it is essential to consult a vet if the behavior persists.

What Are The Tank Requirements For Molly Fish?

Mollies are freshwater fish that live and adapt to various water environments but are adaptable to the environment. They prefer water temperatures from 72 to 80 degrees Fahrenheit and have pHs of 7.2 to 8.

They grow to 4 inches and prefer 2 and 3 inches, respectively. 

However, certain tanks must be provided to ensure the optimal health of mollies. These requirements include the presence of a filter, heater, and plants.

The tank should also have plenty of hiding places and good lighting to create a natural environment for mollies.

Molly Fish Tank Size

Molly Fish Tank Size needs to be adequate for the number of mollies you have. A common rule is 1 gallon (3.8 Liters) of water for each inch of fish.

Therefore, a ten gallon tank can comfortably house four to six mollies but can also hold more if the tank is large enough.

It is essential to provide adequate space for your mollies and ensure that water parameters are correctly monitored and maintained.

Lastly, it is vital to ensure that you have tested and balanced the water in the tank before adding your molly fish, as they are sensitive.

Do Molly Fish Swim at Bottom of Tank?

Molly fish usually prefer to swim in the mid-level and bottom of a tank. They have plenty of space to explore, hiding spots, and plenty of food available.

They can also find other mollies to interact with and a more stable temperature, which is preferable.

However, if the water parameters are not adequately maintained, mollies may become stressed and swim near the top of the tank in search of oxygen.

Why Is My Molly Laying at Bottom of Tank?

Why Do Molly Fish Stay at the Bottom of the Tank? Molly fish staying at bottom of tank could be a sign of sickness. If your molly is lying at the bottom of the tank, it could indicate something is wrong with its health.

Molly fish can often be found lingering at the bottom of their tank, which may indicate improper care or illness.

How to Tell If a Molly Fish Is Dying

Swim bladder infections, ich, and pregnancy can all cause Mollies to reach for lower depths in search of suitable habitat – so keep a close eye on your water conditions!

Other causes could be poor water quality, parasites, and bacterial infections.

It is crucial to monitor the tank’s parameters and take the necessary steps to ensure the optimal health of these fish. If the fish continues to show signs of distress, consult a vet for diagnosis and treatment.

Treating Molly Swim Bladder Disease

It will aid with the treatment of swollen bladder disease in aquariums. A lack of appropriate parameters may cause a severe problem.

Temperature drops have a significant negative influence on digestion. It is essential to keep the water parameters stable, and you need to conduct frequent water changes.

If your molly fish develops swim bladder disease, you must correct the tank water parameters before attempting any treatments.

This could involve raising the temperature or adjusting the pH level of your tank.

You may also need to add medications like antibiotics or other treatments such as Epsom salt baths. Ultimately, it is crucial to seek professional advice to ensure that your molly fish receive the proper treatment.

By providing a safe environment with optimal tank requirements, you will ensure the best possible health of your molly fish.

Do Pregnant Mollies Stay at the Bottom of the Tank?

Pregnant molly at bottom of tank is expected behavior. They tend to look for safer and calmer areas of the tank that protect them from predators.

During this period, it is essential to keep the water parameters in check and ensure that the water is properly aerated.

Additionally, providing plenty of hiding places for the pregnant molly and a nutritious diet is essential.

When mollies sit on the bottom or swim close to substrates, the signs could indicate their pregnancy. You may have a pregnancy-related problem if the baby does not show signs or symptoms.

How To Tell if Your Molly Fish Is Pregnant?

Many Molly fish owners are unsure how to tell if their fish is pregnant and when the baby fish will be born. 

If you are one of these people, don’t worry, you’re not alone. Most fish farmers don’t know how to tell if their molly is pregnant.

This breed mollies video shows you how to determine if your molly is pregnant and give birth. We also discuss the signs that molly is ready to give birth.

What to Do If Your Molly Laying on Bottom of Tank? (Molly Fish Tank Setup)

If your molly is lying on the bottom of the tank, it could indicate poor water quality or illness. It is essential to check the water parameters and ensure they are within the correct range.

Additionally, providing suitable hiding spots and a nutritious diet can help reduce stress in your balloon mollies. If the problem persists, it’s best to consult a vet for diagnosis and treatment.

In conclusion, proper care of Molly fish is essential for their health and well-being. Monitor the water quality, provide them with plenty of space, and ensure that their diet is sufficient. With the proper care, your mollies will thrive and be happy in their new home!

Do Molly Fish Sleep on Bottom of Tank?

Molly fish can sleep either at the bottom or middle of their tank. The exact position will depend on their mood and water conditions.

If the water is too cold, they may tend to lay closer to the substrate in search of a warmer environment. They may also rest near hiding spots, providing a sense of security from potential predators.

It is important to note that Mollies do not need to rest on the bottom of the tank to survive and can move freely around their habitat.

However, if you notice that your molly is sleeping at the bottom for an extended period, it could be a sign of poor water quality or illness and should be monitored closely.

How To Prevent Common Molly Illnesses

If the water inside your tank is a problem, it must be appropriately treated. The easiest solution is to use garlic. Garlic can be used as a promising treatment for ICH because it’s incredibly antiparasitic.

A little garlic is inserted in the fish tank so the fish will not get sick and should be nourished. Garlic has been proven to be bacterial and antifungal, so it can reduce symptoms and prevent rot.

Here are ways to prevent common molly diseases:

Feeding the Fish Properly

It would help if you did not feed a molly that hasn’t stayed above it. Mollies need feeding twice daily. Also, they need enough meals to get through 2-3 minutes.

Molly Water Modification

Molly aquariums need a frequent changes of water. Only then are concentrations of ammonium controlled. Water changes only sometimes suffice. It requires good cleaning filters to remove the particles and the tank clean.

Proper Lights And Heater

Mollies have no special illumination requirements. Since the fish like the water during the night, they used low-intensity lamps more effectively. Then you can see how the fish move at night.

Please make sure the Molly Fish is getting enough sunlight, but no more, as this will increase bacterial growth on their skins. You can also use heating to keep water cool and keep them in good health.

Taking Care of Swim Bladder Illness

It could help with the treatment of swimming and bladder problems. Problems can get worse after incorrect settings. Low temperature causes gastrointestinal problems.

The moll will have the ability to run fast for at least 72 hours after the tank condition improves. It also helps them digest foods already inside their systems.

Use cooked peas to prevent constipation during fasting. Ensure that the food remains at at least three days at room temperature.

Things That Determine Where Molly Fish Will Swim In The Tank

Molly fish can swim anywhere within tanks. Several aspects determine if the occupant will remain in the center and hide under the surface. This includes:

  • Tank size
  • Water temperature
  • Presence of other fish and predators
  • Aquarium decorations and plants
  • Oxygen deficient tanks levels
  • Presence of food and other resources

Considering all the above factors, you can create a comfortable and safe environment for your Mollies to swim in. This will help them stay healthy and active while avoiding any stress or anxiety that can lead to illness.


Though it’s a common question, there is no easy answer to “where do mollies swim in the tank?” The best way to observe your fish and figure out their preferred swimming level is watching them. However, if you’re still unsure where your molly fish are comfortable swimming, you can place various plants at different levels in the tank. By experimentally changing your aquarium’s layout, you may find the perfect spot for your mollies to call home.

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About Me

I am the founder of, a devoted wife and mother, and an avid fish enthusiast. My aim is to assist fellow fish lovers worldwide in understanding how to properly care for and breed their pet fish.

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