Can Gouramis Live With Mollies? (And How To Make Them Coexist)

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As I started my gourami tank, I decided to go with a molly as well. However, I wasn’t sure if the two would be able to live together. As time passed, I learned that it is possible to grow both creatures together, although you should first take care of a few things.

Gouramis can live in the same tank with mollies since both fish have similar water requirements, including temperature, pH, and hardness. Also, mollies and gouramis are comparable in size and relatively peaceful, making it less likely for them to attack one another.

As we move forward, I will take you step-by-step through the proper tank setup, aquarium maintenance, and feeding habits of gouramis and mollies. Following this guide will allow you to grow both species with ease.

Also Read: 19 Great Molly Fish Tank Mates

Gouramis And Mollies: Can They Live Together?

Yes, gouramis can live with mollies. Mollies appear on every list of suitable tankmates for gouramis.[1] The reverse is also true. If you have a molly fish aquarium, many aquarists will recommend gouramis as potential tankmates.

Naturally, you have exceptions. The aquarium community is filled with stories of fish owners whose gouramis attacked their mollies or vice versa. But these occurrences are rare. The consensus is that gouramis and mollies will coexist peacefully.

If you consider the factors below, you will realize that they support this conclusion:

1. Gouramis Have Similar Water Requirements To Mollies

Can gouramis and mollies live in the same water? Yes, they can. Gouramis need 74 to 79 degrees F and neutral or slightly acidic water.[2] In the wild, they inhabit slow-moving water. They are also hardy enough to survive in less-than-ideal conditions.

The swampy areas they occupy are unappealing for many fish because the water is shallow. But gouramis will survive the oxygen-deficient conditions in such settings because they have a labyrinth organ that allows them to extract oxygen from the air at the surface.

If push comes to shove, they can live in tanks with the wrong parameters. They won’t thrive. But they will survive. Fortunately, they don’t have to. A molly fish aquarium doesn’t differ that drastically from a gourami tank. 

Mollies require environments with a temperature of 72 to 78 degrees F and a pH of 6.7 to 8.5. Hardness should fall somewhere between 20KH and 30KH.[3] As you can see, gourami can live comfortably in the same conditions that a molly fish enjoys. 

This is important because the wrong parameters can cause fish to misbehave. The fact that gouramis and mollies appreciate the same water conditions means that you do not have to cause distress in one fish to accommodate the other.

2. Mollies And Gouramis Are Similar In Size

For the most part, size is not an issue. Dwarf gouramis, one of the most common types, have an average size of 3.5 inches. 

Some are smaller, while others are larger. But they rarely exceed 4 inches. They are a perfect match for Mollies, which can grow to a size of 4.5 inches.

Fish are more likely to eat creatures that can fit in their mouths. Gouramis are too big for mollies to eat, and the reverse is true as well. Mollies cannot fit in the mouths of dwarf gouramis.

However, as you probably noticed, the average size of a molly fish is specifically compatible with the average size of dwarf gourami. 

Giant Gouramis are an entirely different matter. They can grow to a size of 24 inches.[4] You need 250 gallons of water to house the adults. 

Pearl, Gold, and Opaline gourami are not as large as Osphronemus Goramy (Giant Gourami). But they are also larger than the typical molly fish.

To prevent the gouramis from accidentally eating their molly fish neighbors, try to limit your selection to smaller types like Honey, Sparkling, and Dwarf Gourami.

3. Both Gouramis And Mollies Are Peaceful

Gouramis are peaceful, although this doesn’t apply to every single gourami. Kissing Gouramis are semi-aggressive.[5] They can also grow to a length of one foot and use their rasping lips to bite other fish.

Paradise gouramis are only 4 inches long, but they have aggressive mannerisms, making them a challenge. Three-spot gouramis are 8 inches long. They have a semi-aggressive temperament.

If you can stick with types such as Honey Gourami and Pearl Gourami, you can trust them to live peacefully with their neighbors. 

The list of semi-aggressive or fully aggressive gouramis is longer than you think. Talk to your retailer before you make a purchase. They will steer you in the direction of peaceful species. 

Admittedly, even with Dwarf Gouramis, the territorial attributes in the males may compel them to fight one another. But a large aquarium will solve this problem.[6] It gives multiple males the room they need to create and protect their territories without fighting each other.

Mollies are in a similar boat. They are peaceful, social, active fish that thrive in large groups.[7] They do not have a reputation for clashing with their kind or fish from other species. 

4. Mollies And Gouramis Share The Same Food

Gouramis and mollies have similar feeding habits. As omnivores, they eat animal and plant matter. You can sustain them by giving them blood worms, brine shrimp, freeze-dried meat, and algae wafers, to mention but a few.

For some people, gouramis are a concern because they are slow eaters.[8] This makes them vulnerable to faster, more energetic fish that can steal their food. 

But mollies are not a problem. Yes, they are active fish. But it would be inaccurate to call them energetic. They have no interest in fighting for food. 

In fact, just like gouramis, mollies require slow-moving water. Gouramis and mollies may clash if the food in their environment is scarce. But otherwise, you can trust them to behave.

How To Make Gouramis And Mollies Coexist?

People expect gouramis and mollies to get along. But that doesn’t always happen. In some cases, gouramis will bully their molly fish tankmates. In other situations, larger mollies will attack smaller gouramis. 

If your tank has the misfortune of housing violent gouramis and mollies, you can use these steps to control their aggression:

1. Improve The Water Quality

You have to make water quality a priority. Dirty water with the wrong parameters can turn the most peaceful gouramis and mollies into savages. If your fish occupy a neglected tank, you can encourage the gouramis and mollies to behave by improving their water quality.

That means buying a testing kit and testing the water to ensure that the temperature, pH, and hardness are accurate. If the parameters are wrong, try to make gradual changes to the water.

These are the ideal water parameters in a tank with gouramis and mollies:

  • Temperature: 74 to 78 degrees F
  • pH: 6.8 to 7.8
  • Ammonia and nitrites: 0 ppm.
  • Nitrates: Below 0 ppm.
  • Water Hardness: 20 to 30 KH.

To monitor the pH, ammonia, nitrates, and nitrites, I use the API Water Test Kit (link to Amazon). You can’t go wrong with that bundle. It comes with comprehensive instructions and lasts for hundreds of measures. It is also impressively accurate.

Bear in mind that suddenly altering the pH, temperature, and hardness will harm your fish. The resulting stress could make them even more violent. You have to raise or lower the parameters slowly until you attain the right figures.

Gouramis and mollies want stability. If they have grown accustomed to a dirty tank with the wrong parameters, cleaning the tank and fixing the parameters overnight will make things worse.

2. Conduct Regular Water Changes

Aquariums use filters to remove pollutants from the water. But filters are not enough. You cannot trust them to remove every single piece of debris, and neither can you rely on them to eliminate toxins like ammonia and lead.

Filters must work hand-in-hand with regular water changes to keep the water clean. A water change will dilute the toxins, bringing relief to the gouramis and mollies and alleviating the stress that was causing them to act aggressively.

However, like the parameters, you have to limit the frequency and size of the water changes. A large water change will alter the chemical balance of the tank. The resulting instability will make the violence in the tank even worse.

That is why I recommend changing 30 percent of the water weekly. Relatively large tanks (20 gallons or more) may require 15-20 percent. Ultimately, the best way to decide is by checking the water parameters. If ammonia spikes or the pH drops, make larger changes.

3. Choose The Right Male-To-Female Ratio

Male gouramis have strong territorial attributes that can drive them to fight one another. Male mollies are not as territorial. However, they can also act aggressively towards other males.

In both cases, if you want to maintain peace in the tank, you should keep one male fish and multiple females. If you want multiple males, get a bigger tank, one that prevents the male fish from repeatedly encroaching on one another’s territory. 

4. Scatter Some Plants

Fish can use plants to hide from bullies. Plants will also alleviate stress. You can eliminate the violence in a tank that has gouramis and mollies by adding plants and decorations.

Female mollies will appreciate the hiding places, mainly if they exist in small numbers, because male mollies are a little too enthusiastic where mating is concerned.

Smaller gouramis can also use hiding places to escape the attention of larger gouramis. If you can maintain the peace among the gourami and molly communities in the tank, the two species will coexist. 

Violence in one group of fish can quickly evolve into a fight with the other species. For instance, if the gouramis fight each other incessantly, they may eventually turn their aggression towards the mollies.

Also Read: Do Angelfish And Mollies Get Along?

Why Is My Molly Fish Attacking My Gourami?

Mollies usually attack gourami fish due to stress. That could be secondary to an overcrowded environment or inappropriate water conditions. Also, if the mollies’ school is too small, they will become aggressive to protect themselves.

If your molly fish is attacking your gourami, this is what you should know:

  • Lack of food – Because gouramis and mollies eat the same food, a scarcity of food in the tank can drive larger mollies to attack smaller gouramis during mealtimes. A large molly may even attempt to eat smaller gourami if the fish is truly desperate for food.
  • There are too few mollies – Mollies are shoaling fish. They are happiest in groups. Some mollies can live alone without suffering any significant consequences. Others may struggle with stress. But generally, they feel safe in groups. 

By forcing them to live alone or in small numbers, you have eliminated their sense of security. They may respond to that stress and lack of security by attacking any tankmate they perceive as a threat.

  • The tank is overcrowded – Peaceful fish can become violent if you force them to share a crowded environment. This is true for mollies. If you have too many fish or the tank is too small, their territorial attributes will drive the mollies to attack the gouramis. 
  • Inappropriate conditions – Poor tank conditions like the wrong pH and extreme temperatures will push the fish in your aquarium to turn against one another. The peaceful temperament for which the molly fish is known will disappear once the water quality deteriorates.

Also Read: Can Mollies Live With Goldfish?


Mollies and gouramis can be perfectly happy in the same aquarium. But you should bear in mind that in some instances, aggression can be a natural part of the interaction between the two species.

To preserve the peace in your tank, you need to maintain a balanced environment that will eliminate any factors that may drive mollies and gouramis to fight. Start by adjusting the water parameters, including pH, temperature, nitrites, nitrates, and hardness.