Mollies: Quick Guide To Keeping These Common Freshwater Aquarium Fish


Do you want to keep some of the most exotic freshwater fish in your aquarium? How about you get Mollies? Trust me, you won’t regret it. 

Mollies are live-bearer fish that are adaptable, but some species can be a little hard to keep sometimes. Most species of Mollies are resilient and easy to take care of, making them a great choice for people who are beginners at pet fish keeping. 

These beautiful fish are also very peaceful and adjust well with other fish in the community. Also, they are one of the most popular fish. You will probably find them in every fish store.

Ideal Habitat

Mollies hail from streams and rivers of Northern and Southern America. They prefer to stay in the shallow waters where the current is slow and the temperature is warm.

There are sandy substrate and a lot of plants. So, keep in mind that you would have to replicate this environment in Mollies’ tank.

Tank Size

Typically, A Molly needs at least a 10-gallon tank. You can keep up to 4 Mollies in a tank of this size. However, that depends on their species.

  • Rule of thumb: Each Molly you add will need an additional 3 gallons to live conveniently and comfortably. 

Tank Set-Up

Temperature: Mollies’ tank needs a heater to keep the temperature between 72 to 78-degree Fahrenheit. This is because they hail from tropical regions where waters are warm. 

pH: Since the pH of water in North and South America tends to be slightly alkaline, you should keep the pH of the water in Mollies’ tank somewhere around 6.7 to 8.5. 

Water hardness: This should be kept between 20 to 30 KH. 

Substrate: You can keep one layer of a sandy substrate at the tank’s bottom. It will do its job of making Mollies feel closest to their natural habitat.

Plants: Mollies love plants. They take shelter in them but are also important in reproduction. You can choose any plants you like. Taller ones including Anubias nana provide suitable shelter for Mollies who like to swim at the middle of the water level. 

Ammonia levels: Keep the ammonia levels near to or at 0 ppm. 

Nitrate levels: The nitrate levels should be at 0 ppm. 

Decorations: Put a lot of rocks. Those will make cave like structures that help Mollies to hide if other fish are harassing them. 

Tank Mates 

Mollies are peaceful fish and like the company of other calm fish. Let’s see which types can prove to be good tank mates for Mollies. 

  1. Cherry Barbs
  2. Danios
  3. Corydoras Catfish
  4. Dwarf Gourami
  5. Rosy Barbs
  6. Tetras
  7. Harlequin Rasbora
  8. Zebra Loaches
  9. Platies
  10. Yo-yo Loaches
  11. Shrimp
  12. Snails

You should avoid keeping Mollies with larger and more aggressive fish. They may attack them, attempt to eat them, and cause them to feel anxious. Anxiety can even lead to death. 

  • Can you keep Mollies with other Mollies?

Yup, Mollies can be kept together. You can put 4 in a group. However, make sure that there are more females in the group as males tend to be harassers when it comes to living with their female fellow fish.


Mollies are omnivores. Their diet can have a variety of items ranging from plants to invertebrates. However, they prefer to eat plants.

Here’s what you can feed your Mollies.

  • Plants
  • Algae
  • Lettuce
  • Spinach
  • Zucchini
  • Flakes
  • Pellets
  • Live food
  • Frozen food
  • Bloodworms
  • Brine Shrimp

Feeding routine: Give them food two times a day. The amount should be enough to be eaten in 2 minutes.


Mollies are adaptable. Still, they need their tank to be clean.

Cleaning routine: You should clean their tank once every week and change 20% of the water.

Don’t forget to scrub the walls and do a deep cleaning every once in a while. Dirty tank conditions can lead your Mollies to suffer from health diseases that can be fatal. 

Make sure the rocks and plants are clean too, as Mollies love to hide in them. 


That’s it, folks! All that Mollies’ knowledge is now transferred to you. I am sure you are pretty excited to get Mollies and keep them in the aquarium. You will love the sight, believe me. 

Proper care and never-ending love will help you form a connection with your fish. I hope you enjoy and cherish that.

John Kilmerstone

I love keeping pet fish and receive a lot of joy and peace from watching these colorful creatures. Please visit this website and explore the wonderful world of pet fish. Discover how to care for and look after pet fish and amplify your satisfaction.

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