Mollies vs Platies: Which Fish is Right for Your Aquarium?

If you’re wondering whether you should keep mollies or platies in your fish tank, then you’ve found the right article! In this article, not only will you find out the differences between both fish, but you’ll also learn their tank requirements, what they need to eat, and whether they work well together as well!

So keep reading to find out everything you need to know!

Molly Overview

Some of the most stunning and unique live-bearing fish are found in the genus mollie, or mollienesia, as it was once known. The sailfin molly may be the most exotic fish you can buy. Mollies are best suited to freshwater, but you can also find them in saltwater situations like lagoons and brackish ditches. In addition to harbors, the waters close to the roots of mangrove trees are also suitable habitats for some mollies.

Freshwater molly fish have been a favorite of aquarists for quite some time. These fish are popular due to the abundance of species available and the ease with which they may be cared for. However, despite how easy they are to care for, we always recommend that owners educate themselves thoroughly on this species. In addition to keeping them content and healthy, this will also free up some of your time.

Tank Requirements 

Mollies, like all fish, do best in an environment that mimics and meets their requirements for their natural habitat. Throughout the coasts of North, Central, and South America, mollies are most commonly found in areas with slow-moving creeks and streams. Although they thrive best in heavily vegetated environments, researchers have discovered that they can survive in brackish and even oceanic waters.

Tank Size

Mollies can do fine with a smaller tank than what is typically recommended. One of the smallest species, the Short-Finned Molly, is able to thrive in a tank as small as 40 liters (10 gallons). A 115-liter (30-gallon) tank is suitable for all but the largest species. It’s best to provide your Mollies with a larger tank because of the increased stability and reduced susceptibility to fluctuations it provides.

Tank Water Condition

Molly fish are able to adapt to both freshwater and saltwater habitats, demonstrating their extreme resilience. Freshwater between 25 and 28 degrees Celsius (72 and 82 degrees Fahrenheit) and a pH between 6.5 and 8 is ideal for them. It’s not necessary to have a tank with special filtration for mollies, but doing so is preferable because some hybrid varieties are more prone to disease than others. A pinch of salt may be added by some aquarists.

Tank Decoration

A sandy substrate is ideal for mollies’ tank floors. While mollies preferred live plants may not spend much time in the aquarium’s sand, the substrate is fine for them. You can provide your Mollies with some much-needed cover by including some tall plants in their tank, such as Anubias, but you should be aware that they may eat any live plants.

Provide your Mollies with decorations that form caves and crevices to ensure the safety of this docile fish.

Lyretail molly Poecilia latipinna aquarium fish  in the fish tank(aquarium)


A molly will eat almost anything you throw at it. For optimal health, it’s best to give your Molly a diet rich in variety. Fresh, frozen, and flake foods are all appropriate for feeding Mollies in an aquarium setting. Feed your Molly a high-quality flake food, some vegetables, and an occasional protein treat.

Mollies thrive on a diet rich in vegetables as well as spirulina and peas. Protein-rich bloodworms, brine shrimp, daphnia, blackworms, and worms can be purchased fresh or frozen.


The majority of Molly species have an extremely high reproductive success rate in captivity. Mollies are classified as “live-bearing fish,” which means that the females carry their eggs to term and birth fully formed young. Mollies of both sexes will reproduce indefinitely if left in a tank together, but the adults will eat most of the fry if you don’t take them out. It’s safer for everyone if there are at least three women for every man.

Provide hiding places for the fry, such as dense plants or floating plants like Java moss. Fry has a better chance of making it to adulthood if there are more plants in the tank.


Because of their calm demeanor and friendly nature, mollies are excellent additions to a community aquarium with other fish of the same temperament. Males’ pursuit of females for mating purposes is the only known instance of aggressive behavior. If males are isolated from females for too long, they can become aggressive and start biting other fish’s fins.

Though they aren’t shy by nature, mollies do better in environments with plenty of hiding spots, such as cracks, crevices, and plants.

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Platy Overview

Among the many species of live-bearing freshwater fish, Platys are a favorite among aquarists. The platy is a member of the Xiphophorus genus, which also includes its close relatives the swordtails. They are hardy, can live with other fish, and are very easy to breed. They are also available in a wide range of glamorous colors and shapes.

There is a wide selection of Platy fish available, the result of both natural hybridization and intentional breeding. Platy fish come in every color of the rainbow, from red scarlet to blue to even black.

Some Platy varieties have been selectively bred to have larger fins, but in general, Platy are laterally compressed fish with small fins and a fan-shaped tail. They are also notable for their elongated shape, which is characterized by a convex belly and a flat back. As is typical of fish that feed at the surface, the mouth is in an upwards position.

Males can grow to a maximum of four centimeters in length and feature an elongated reproductive organ called a gonopodium, while females can expand to a maximum of six centimeters in length and feature an anal fin that is more rounded.

Tank Requirements

Platy fish are found in ditches, backwaters, swamps, and ponds in their natural environments. We can describe these warm bodies of water as slow-moving, somewhat hard, and heavily vegetated. Platy fish are resilient and can adjust to a variety of water conditions, but they will do best in a biotope tank.

Tank Size

Five or six platy fish need a tank that’s at least 10 gallons in size. For every extra fish, add 2 gallons to the tank’s capacity. Because of their energetic swimming, platy fish need a long, wide tank. A tight-fitting tank lid is necessary since platy fish have been known to jump out.

Tank Water Conditions

Alkaline water is best for platy fish. Keep the pH between 6.8 and 8.0, and the hardness between 10 and 28 dGH. The natural environment of a platy fish includes hard water. The filtration system maintains a clean tank with minimal ammonia and nitrate levels. You should stay away from any filtering systems that produce excessive currents. Platyfish prefer calm environments with little current.

Tank Decorations

Platy fish need a large tank with plenty of room to swim and exercise their boundless energy, so be sure to include plenty of plants. Tough plants that can survive with the same amount of water should be used. Hornwort, duckweed, and java moss are all excellent choices. Platy fish are surface-dwellers, thus, floating plant life is ideal for them.

Wagtail Platy Fish, xiphophorus maculatus


In the wild, these fish eat anything they can find. Plants, algae, insects, and thin bark are all in their diet. In order to recreate the above meal as accurately as possible in a home aquarium, it is essential to stock it with nutritious ingredients. The owner should offer them high-quality tablets, live meals, and frozen foods to get a complete meal with all the necessary vitamins and nutrients.

Popular choices for feeding platy fish include flake feeds. Always check the label to make sure you’re getting high-quality flake food. Blackworms, bloodworms, daphnia, brine shrimp, fruit flies, and mosquito larvae are some of the live meals they consume. These items constitute the ideal diet for platys.

Frozen food is a good substitute for live food if you can’t supply it. Frozen blood worms, black worms, daphne, and brine prawns are some of the best foods for platy fish, but they will also eat other live food such as squid and clams.


Breeding Platy fish is a relatively simple process. To breed Platy fish, you don’t need any special tools or to follow any special processes. Almost all Platy fish are able to reproduce, therefore, they can raise their own offspring. Platy fish are notorious for reproducing in even the most chaotic aquarium environments.

Reproductive Period

Platy fish mature rapidly, especially sexually. They begin reproducing between 6 and 8 weeks of age and continue doing so until they die. From twenty to forty fry can be born at once from these females, depending on their size and maturity.

The Mating Process

The male Platy fish will chase after the female and court her, and the eggs will be fertilized inside the female’s body. The entire mating procedure takes only a few minutes. Within 7-10 minutes, a pair will mate. When an egg is fertilized, the egg develops into a chick.

Gestation Period

Platy fish have a relatively short gestation period, 20- 25 days. The duration of a woman’s pregnancy depends on a number of things. The duration of a fish’s gestation cycle is primarily determined by its age. However, the length of time an organism spends in gestation is also affected by the tank water’s temperature, pH, and GH. Platy fish have a short gestation period; thus, they can breed frequently; they have a new litter of fish fry every 30–35 days.


This species does not exhibit any aggressive tendencies toward any other species. They appear to be constantly on the move throughout the day. It’s worth noting that Platy fish are gregarious; thus, it’s best to introduce a small group into the aquarium to ensure the best possible living conditions for all of the fish.

Since males tend to compete with one another during mating season for the attention of available females, it is important to introduce at least three females for every male.

Can Mollies And Platies Live Together?

Platys and mollies are compatible tank mates. Both species have gentle and tranquil personalities, making them ideal tankmates. You won’t have any issue taking care of both platies and mollies at the same time because they have very comparable tank and water requirements.

Do not overcrowd the tank if you want your platies and mollies to live peacefully together. The optimal amount of water for a fish is two to three liters per individual fish. If you’re trying to decide how many platys and mollies to keep, that’s something to think about.

Which Are Better Mollies Or Platies?

It is difficult to choose between these two livebearer species, but mollies have a reputation for being hardier. A higher concentration of aquarium salt is more effective against parasites and infections in molly tanks than in those of platy tanks.

Molly fish can control their internal systems to rid themselves of harmful chemicals and pollutants in the water. Platies are not overly delicate and can even survive tank cycling, but being smaller makes them more vulnerable to illness and toxic medications.

How Can You Tell The Difference Between Mollies And Platies?

Although they look similar, mollies and platies really originate from different families. Since Mollies and Platys are both live breeders, distinguishing between the two can be challenging. It can be confusing to discern the difference between a Molly and a Platy, even if you have experience caring for fish. There are a number of key differences between them that we’ve outlined here.

Differences in Appearance

While both mollies and platies can come in a variety of sizes and colors, there are a few key differences between the two. On average, mollies are bigger than platies. Platies are shorter and more spherical than mollies, and mollies are longer and more slender. While platies have forward-facing jaws, mollies have upward-pointing jaws.

Platy is typically found in red, yellow-gold, orange, and white, while mollies can have cooler tones like orange, black, green, and white.

Mollies, unlike platies, tend to have more intense, saturated hues even while their colors overlap. However, unlike mollies, platies may have a variety of spots across their body.

Difference in Appetite

Although there are similarities between the dietary needs of mollies and platies, which are both omnivores, and include both animal and plant-based foods, these two species have some important dietary differences.

In the wild, platy eat mostly vegetables; however, they also eat small insects and larvae. Spirulina and fish flakes are ideal since they contain more plant material than meat.

However, mollies have a higher protein requirement and should be fed foods like fish flakes, protein pellets, spirulina, and more frozen daphnia.

Another distinction is that platies have a greater dietary demand. You shouldn’t feed mollies more than twice a day for 2 minutes each time, whereas platies can be fed as often as three times a day for 3 minutes each time.

Differences in Behavior

Both mollies and platies are sociable and calm, but there are some important behavioral differences to be aware of.

Both species are community fish that prefer to live in small groups, although platies are more gregarious and require at least five individuals per tank. As they don’t need as much company, a tank with only 3–4 mollies is fine.

When there aren’t enough women around, platy populations can become hostile. As the active breeders that they are, platies require a ratio of roughly 1 male to 3 females to keep them from becoming aggressive.

While mollies rarely show aggression, it’s best to preserve a 1:3 male-to-female ratio so the males don’t worry about stressing out the females.

Differences in Breeding Behaviors

Platys reproduce more frequently than mollies, but each brood is smaller, with an average of 20 to 80 fry. When conditions are right, a molly can hatch a brood of up to 140 young. Platyfish typically have a 4-week gestation period, although mollies can start as early as 3-weeks.

In order to successfully rear mollies, you must keep the adult fish isolated from the juveniles. Adult Platy fish rarely eat their young; thus, it’s not necessary to separate the mother and her young after she gives birth.

Can Mollies And Platies Crossbreed?

The ability of animals of different species to mate and produce offspring is referred to as crossbreeding. You might be wondering which species of fish can successfully hybridize with one another. Have you ever wondered if the mollies and platies in your freshwater aquarium could have offspring? So, the answer is No.

There is no way for mollies and platies to have offspring. Crossbreeding in fish requires a high degree of genetic similarity between the parent species (DNA). Fish in the family Poeciliidae, which includes both platies and swordtails, can mate with one another. To the contrary, mollies and endlers can mate because they are both members of the Poecilia family.

They are all members of different “fish families,” meaning they don’t share a common ancestor. If you have mollies and platies together in a tank and you see baby fish swimming around, it’s likely that one of the fish was already pregnant when it was introduced to the tank.

Livebearers like mollies and platies don’t lay eggs but instead, have their young develop inside of them. Therefore, they are able to store sperm for extended periods of time before showing any signs of pregnancy. It may take a few months after mating before it gives birth. That being the case, it’s likely that the fish reproduced while it was being kept in captivity at the pet store before you bought it.


At first glance, mollies and platies may seem interchangeable, yet, there are some differences between the two. Despite these distinctions, these fish species complement one another, and provided you’ve maintained the right conditions in the tank, they should quickly make your aquarium their new home.

About the author

Hey! I'm Antonio!

Betta fish keeper for over 6 years now! Since owning a betta I've also housed all kinds of tropical fish, and have seen all manner of problems and how to look after them!

If you need any advice you can always message me or better yet join the Facebook group where a community can answer your questions!