Goldfish and mollies are lived in freshwater, but they are from different families. There will be many problems if we put goldfish and mollies live together. Mollies are peaceful fish, but when they become aggressive, they will start killing other fishes. When we research more about goldfish and mollies, there is a lot more to share with you.

Mollies are peaceful freshwater fish but they cannot be placed with goldfish in the same tank. Goldfish require cold water to thrive whereas mollies need warm water. However, we can’t predict the molly’s fish nature because they become aggressive anytime.

There are more reasons too, After research and experience, we could not recommend keeping both mollies and goldfish living together. This blog post will explore more about goldfish and mollies. So keep reading till the end to know more about these fishes.

What is goldfish?

Goldfish is a freshwater fish from Cyprinidae of the order Cypriniformes family. People usually keep goldfish as indoor aquarium pets and it was one of the most popular freshwater fish.

Goldfish can grow up to 2 inches in an aquarium, but if you put goldfish in a tank then they went be bigger in size. In outdoor ponds and wild, people have found 14 inches of goldfish. There are different varieties of gold fishes available in the market.

Some of them are common goldfish, Bubble eye, Comet, fantail, oranda, etc.

Do you see the goldfish breathing slowly in your tank? Be careful because most fish have this problem, So check my blog post to know more about it.

What is molly fish?

Goldfish and Mollies

Molly is a freshwater fish that was popular among fish keepers. These types of fish are low maintenance care required for fishes. Livebearers are the family of molly fishes and these fish are part of the Poecilia genus.

There are different types of molly fish such as black molly, white molly, lyretail mollies, dalmation mollies, etc.


Temperament is an important fundamental of fish keeping. If you’re new to fish keeping then do heavy research about the temperament of fish for choosing the right fish. Fish temperament will range from peaceful to aggressive and habits too.

Goldfish Temperament

Goldfish are social animals with peaceful nature. They can live without harming other fishes ( But I don’t recommend putting goldfish with other fish) They will offer a calm mind without any aggression.

Goldfish need an aquatic environment with a lot of space for swimming, You need to care for them as a pet.

Mollies Temperament

Goldfish and Mollies

Mollies are another freshwater fish with a peaceful mind. However, we are not recommending placing both goldfish and mollies together due to the temperament of mollies.

They can become aggressive. They have the tendency to attack other fish like goldfish. So be careful while putting other fishes with mollies without knowing the temperaments

Apart from temperament, We know that mollies are aggressive and they cannot be put with other fish in a community tank.


Goldfish and Mollies

Goldfishes are not aggressive, they will not fight with other fishes for food. Goldfish are uncompetitive which means they are slow and not hungry for food. Whereas mollies are semi-aggressive fishes that have the tendency to fight and swim faster. So it was easy for mollies to eat food.

This will lead to big trouble, mollies fishes will take food as fast as they could and leading to goldfish overfeeding. So It was not possible to feed both fish in the same tank.

Habitat of goldfish

The habitat of goldfish is, that they are slow-moving in water. They can survive nearly from freezing to 30°C. Moreover, The pH level needs to be maintained which ranges from 6.5 to 8.5.

Goldfish require a good aquatic setup like aquatic live plants, rocks, etc.

Habitat of Mollies

Mollies can be found in freshwater mostly around the southern part of North America and Mexico. They can swim faster and are found in different types of water such as salt, coastal waters, brackish, etc. The pH level needs to be maintained which ranges from 7.5 to 8.5.

They are able to survive a low-oxygen environment and will hide in underwater foliage. 

Tank size

Goldfish and Mollies

The goldfish and mollies need a different tank with different water temperatures. We know that goldfish are social animals that live in good aquatic environments. They love to swim and need space for living. If you put one goldfish, you need to build 20 gallons water capacity tank.

On the other side, Mollies need the tank size according to the type of fish. The other thing is If you want to put 15 pairs of mollies, then you’ll need a 40-gallon capacity tank. Mollies will like to swim faster with good feeding.

What do mollies need in a tank?

Tank SizeMinimum of 15 gallons of water is needed for four mollies, 3 gallons per extra molly fish
SubstanceSand, rocks, Live plants, pebbles, caves
FilterTo remove excess ammonia, nitrate, and debris
Water temperature24°-26.7°C
pH Level7.5 to 8.5
BubblerTo oxygenate Water

What do goldfish need in a tank?

Tank SizeMinimum 30 gallons of water needed for single goldfish, 20 gallons per extra goldfish fish
SubstanceSand, Live plants
FilterTo remove excess ammonia, nitrate, and debris
Water temperature68° to 74° F
pH Level6.5 to 8.5
BubblerTo oxygenate Water

Will goldfish eat Mollies?

Goldfish and Mollies

Goldfish are social animals and they will not hurt or eat other fish, The gold needs to provide good care otherwise it can be dead or decrease its lifespan. You need to maintain a good water temperature and aquatic environment for good fishkeeping.

The goldfish will not eat any fish, they are not aggressive in nature. So be careful while putting goldfish and mollies together in the same tank.

Does molly fish eat other fish?

Mollies are aggressive in nature. They have good swimming ability with good feeding capacity. If you put goldfish with mollies, then mollies will attack the goldfish and kill them if they are hungry. In order to avoid this, you need to feed the mollies the correct time schedule.

We are not recommending putting both goldfish and mollies in the same tanks. There is less chance for the goldfish to swim and feed. Be careful while feeding both fishes because mollies have the ability to swim faster. So they will eat most feed and leading to overfeeding.

Can molly fish eat other mollies?

After reaching and experiencing it, can’t say that mollies will eat themselves. Maybe they eat fry but have no chance to eat other mollies. However, don’t take a chance. Feeding at the correct schedule will decrease the tendency to eat other fish.

If you want to know that goldfish can live alone. I’ve posted a detailed article! do check it.

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