Molly Fish Care Guide | Size, Tank Mates, Breeding Info

Molly fish, also known as mollies, are a resilient and easy-to-care-for freshwater fish native to Mexico and the Southern United States. Mollies, which belong to the Poeciliidae family, may be found in freshwater rivers and estuaries, as well as infrequently in seawater. They have an exotic appearance and will bring variety and variation to your aquarium. The molly fish is popular in the aquarium trade because it is easy to care for, and it is closely related to the guppy.

Temperament Peaceful
Lifespan 5 years
Family Poeciliidae
Minimum Tank Size 10 gallons
Care Level Easy
Color Varied
Size 4.5 inches maximum
Diet Omnivorous

Molly Fish Care Guide

Because of their resilience, mollies are quite popular. They’re simple to care for, making them an excellent entrance point into the world of aquariums for newcomers. They may be obtained in practically any fish market and at a reasonable price because to their popularity. They are generally freshwater fish, although owing to their versatility, they can occasionally be found in seawater.

While they don’t require much, they do necessitate a clean habitat and enough water supply. Poor water quality can induce “molly illness,” a disease called after mollies due to its prevalence. If your mollies contract molly sickness, they will become less active and may even exhibit strange motions such as wriggling.

It’s time to examine the water quality if your mollies start acting like this. Molly illness isn’t too tough for these aquarium fish to recover from. They will be happy and thriving once the water conditions have returned to normal. Molly fish Care are susceptible to a variety of freshwater fish illnesses, including ich. Close examination of their scales and changes in everyday behaviours might reveal this.


Albino mollies have a pale to white coloration and crimson eyes. Mollies of various colours, including orange, brown, and even gold, can also be found. Sexing the molly fish is simple. Males are typically bigger than females and have a sailfin, which females do not have. During pregnancy, when the females plump up and grow a black mark on the base of the anal fin, their distinctions become much more noticeable.

Size & Color

What is the maximum size of a molly? Mollies in the wild can grow to be up to 5 inches long. In captivity, however, they are slightly smaller than most other aquarium fish. They should reach a length of 4.5 inches in your aquarium.

Let’s take a closer look at some of the numerous varieties of mollies.

  • Black Molly Fish
  • Lyretail Molly Fish
  • Sailfin Molly Fish
  • Balloon Molly Fish
  • Dalmatian Molly Fish
  • Red Molly Fish
  • Orange Molly Fish
  • White Molly Fish

Lifespan Molly Fish

What is the lifespan of a molly fish? In captivity, the molly can survive for up to 5 years. The best and safest approach to ensure that your mollies enjoy a long and healthy life is to keep the aquarium clean and frequently monitor water conditions.


Mollies are freshwater marine organisms endemic to the southern United States and Mexico, and they belong to the poeciliidae family.

Tank Mates

Mollies, fortunately for novices, do not require a special tank configuration. This is due to the fact that they have been reared in captivity for many years and have grown well-adapted. When keeping mollies in a tank with other fish, you should prioritise the requirements of the other species before the mollies’. Simply to retain flora in your tank, a sandy substrate is recommended.

Give these small fish with large personalities stuff to do, such tall plants to hide between, to keep them happy. Allow them to explore fake caves and rocks to satisfy their innate curiosity. Because they are tropical fish and are accustomed to warmer water, you may need to invest in a water heater to keep the temperature consistent.

Temperature and Water Condition

Mollies should be kept at a temperature of 72-78 degrees Fahrenheit (22-25.5 degrees Fahrenheit). They will adapt to aquarium life easier with these water conditions because this is the natural temperature of freshwater estuaries where they are native.

Minimum Tank Size

For 1-3 mollies, we recommend a 10 gallon tank as a beginner, but bigger species will require larger tanks to begin with. When the number of people in the tank reaches three, the tank should be doubled in size.

Maintenance and Care

Mollies are a robust and versatile species of fish. To keep the aquarium ecosystem in good shape, you should always remove any remaining food. Aside from that, you may change out the water and adjust the water quality to accommodate more sensitive species in your aquarium.

It’s also a good idea to change the water out as needed for different species. As long as the water conditions are acceptable to the mollies, they may adapt nicely. They can even survive in saltwater for brief periods of time if necessary.

Suitable Tank Mates

Fish that are peaceful are the simplest to locate tank mates for. Mollies get along with other peaceful species (of similar size) in a community tank because they are such a kind species. Although, because crowded environments can trigger a molly Fish hostility, make sure tanks are spacious enough for all species.

Regardless of size, stay away from aggressive fish. Because mollies are cleaner fish, they get along with other invertebrates who provide the same function. Snails and shrimp can be put to community aquariums to help keep the water clean.


Mollie fish mate in a unique way. The molly fish’s mating preferences have been studied in relation to the environment. What’s interesting about mollies is how they gestate their young, which isn’t typical in other fish. Mollies are called livebearers because they do not lay eggs. The ladies wait for their eggs to grow inside them before releasing them.

If you want to breed your mollies, you’ll be relieved to learn that they are simple to breed in captivity and will do so on a frequent basis. The aquarium conditions are something you should keep an eye on. To induce mating, you must keep everything in perfect order.

When the males begin to court the ladies, you will know you have succeeded in initiating mating. Females are in charge and will only allow males to fertilise the eggs when they are ready. Males can become irritable and try to “sneak attack,” but this is frequently ineffective, and the females will react. You may also guess which male the female will choose to mate with (if there are more than one). Female mollies will frequently prefer the aquarium’s biggest male molly.

When you’re done, the female’s tummy will start to enlarge. When compared to other mollies in the same aquarium, it will be obvious.


Mollies are a breeze to look after in every way. It’s simple to keep them alongside other fish, and they’re noted for having vivid personalities. This is why getting mollies is a no-brainer, especially if you want a variety aquarium with bursts of colour. They’re also a simple species to include into an existing aquarium. You only need to ensure that the aquarium’s settings are optimum and that they are fed the proper amount of food.

The lifetime of your aquarium fish is also dependent on well-balanced food and nutrients. Keep up to four mollies in the same tank when introducing a new school.