Can Guppies and Mollies Live Together?

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Written By Fun Fish Tanks

I Love my Fishes 

All the aquarists wish to pair species of fish that are compatible with each other. One must not just wish, but it is crucial to keep species that go well with each other. If the fish species are not fit enough to be kept together, your aquarium will become a disaster. So it is of prime significance that one must research thoroughly first before adding different species of fish together. 

Speaking of different species, Guppies and Mollies are popular species in the aquarium hobby. These are magnificent species of fish, and everything adds up to them being ideal for an aquarium. In this article, you will find all the information you require on keeping Mollies and Guppies together. 

Can you keep Mollies and Guppies together? 

Mollies and Guppies are congruent species of fish, and keeping them together in an aquarium is one thing you can go for. These two species are capable of living together without posing any disturbance to each other. But there are things you must know before keeping these two majestic fishes together.

Behavior and temperament 

Behavior and temperament is the first thing that comes to one’s mind when thinking of keeping different species together in a tank. Why wouldn’t it? It has crucial significance regarding the compatibility of two different species.

With all this said, let us see whether the behavior and temperament of Mollies and Guppies go hand in hand or not. 

Molly’s behavior and temperament 

Mollies are peaceful species of fish. They are also active and you can see them swimming around happily in an aquarium. They face no problems in getting along with other fish species. But if the tank is overcrowded leaving them with minimal space in the aquarium, they are inclined towards aggressiveness. An aggressive Molly is not good for a Guppy as it will nip its fin. 

Also bear in mind that when you keep several Mollies together, make sure that there are more females than males. You can also simply keep females only in a tank

Guppy behavior and temperament

Guppies are peaceful species of fish. Even if an obvious situation arises, they won’t become aggressive like the Mollies. Guppies get along with all the fish species and will never go towards aggressiveness in their lifetime.

But since they’re peaceful, don’t keep them with aggressive fishes as they will get bullied. They prefer swimming around and if you notice them hiding frequently then you have a bully in your tank. 

The only instance that they will show aggression is if you have a high number of male guppies in a tank. Similar to the Mollies, you must have a greater number of females than the males.

Diet and Feeding of Mollies and Guppies 

Diet is a crucial aspect when it comes to keeping different species together. Mollies and Guppies have a similar kind of diet, so there is not much hassle in this criteria. Both the fish species are omnivores, therefore you have to feed them a mixture of vegetables and meat. 

First of all, you can give Mollies and Guppies vegetables like lettuce, zucchini, and many more. Make sure that you blanch the vegetables before feeding them to them. Also, you can add live plants to your aquarium, it will also serve as the food most of the time. You must also feed them flakes. With flakes, the Mollies and Guppies will get a lot of nutrients. 

Live foods are also essential for these two species. But you must feed live foods occasionally and not always. With live food, they will be getting abundant nutrients necessary for their well-being. You can give Mollies and Guppies brine shrimp, bloodworms, mosquito larvae, and daphnia. Although feeding too much live food is not good and must be given as treats. 

You can feed the Mollies and Guppies twice a day, and give them small portions. They are vigorous eaters and will eat even if full. So don’t fall for their hungry appearance after you have fed them well. Giving them too much food will lead to constipation and your tank will be full of fish waste as well. 

Water Temperature and Water Parameters

This is another aspect one must not look over. Luckily in the case of Mollies and Guppies, there is not much headache on this part. They have similar preferences for water parameters, and keeping them together is not a problem at all. 

Molly Water Parameters 

Mollies prefer the water temperature between the range of 75℉ to 82℉. The pH levels preferred by them lie between 6.8 to 7.8. 

Guppy Water Parameters 

For Guppies, the tank’s temperature should be kept between 72 and 79 degrees Fahrenheit, and the pH should be between 6.8 and 7.8.

Tank requirements

Molly Tank Requirement 

For Mollies, the minimum tank size that one can go for is 20 gallons. Although larger tanks are recommended. In a 20-gallon tank, you can keep a maximum of 3 Mollies, if you want to add more then increase the size of the tank by 3 gallons for each Molly. 

The substrate of the tank must be a sandy one for the Mollies. Remember to add plants as well, for Mollies love plants. 

Guppy tank requirements

Guppies must be kept in a minimum tank size of 10 gallons. They are not choosy for a substrate, and you cannot keep one as well. But remember to provide a lot of plants for Guppies. They require places to hide as their temperament is peaceful. You can add Java Moss, Java Fern, and Anubias. Caves, Decors, and driftwood also do the job.


Both of the species, the Molly and Guppy are livebearers. They are expert breeders and can breed under the right tank conditions. Mollies can breed once every month, and Guppies are similar as well. Mollies can produce 10 to 60 babies, and Guppies can give birth to 20 to 50 babies at once.

Both Mollies and Guppies eat their young. Although they won’t eat all of them, some can survive and grow to become adults. So if you wish to raise the fish fry, you should remove the parents after they have given birth. 

Breeding can be a problem as they can breed without any hindrance, and the females can keep the sperm for future reproductions as well.

Mollies can store up the sperm for about 3 months, and Guppies can store and use sperm for a lifetime. If you don’t want the Mollies and the Guppies to breed, then you should keep only one sex of fish in a tank. You can also keep the Mollies in lower water temperatures to as not to stimulate breeding. 

Can Mollies and Guppies breed with each other? 

These two species can crossbreed together. It can happen if one species cannot find the opposite sex to breed. So in such a case, a Molly can breed with a Guppy and vice versa. But this happens once in a blue moon, and don’t expect to see it in your tank of Mollies and Guppies.

Should you keep Mollies and Guppies together? 

The answer to this would be yes, if you want to keep Mollies and Guppies together you should go for it. The diet, tank requirements, and water parameters are on the same line. You will have no problem keeping them together. Although you must not overcrowd the tank and always keep a greater number of males than females. Breeding might become troublesome as they reproduce frequently. But if you are a breeder then you are in for a treat.

So there is no problem in keeping these two species together. They seem to be a match made in heaven. Therefore don’t hesitate if you want Mollies and Guppies in a tank. They both are peaceful. But Mollies can become aggressive if you overcrowd the tank. Give them the preferred water parameter ranges, and they won’t have any problem coexisting with each other.

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