Can Molly Fry Survive In Main Tank? Risk & Benefits

Molly fry is the hardest to care for of all fish pets. Molly fish is also often the most expensive because they grow much slower than other types of fish and require more attention. But can they survive in the main tank? This is a question many people ask themselves when deciding what to do with their aquariums. They may be able to, but it depends on how you set up your tank and other factors discussed below. If you want to find out more, read on!

Molly fry can survive in the main tank with enough aquatic plant life and other hiding spots. However, they will grow at a high-speed rate, so it is important to ensure they have as much room as possible to move around without bumping into each other or plants. To give Molly fry a chance of survival, use some form of natural filtration like live rock or polypore filters – this helps filter out any harmful materials.

In this post, I will discuss why you should not put Molly fries in your tank, as well as why you should put them there so you can make up your mind about what to do!

Can Molly Fry Survive In Main Tank?

Molly fish is a type of livebearer fish that can survive in the main tank. They are also famous as Molly minnows. They resemble adults, and they reach adulthood within six months of being born.

If you want to keep Molly’s fry alive, there should be enough aquatic plants and other hiding spots to cover predators like goldfish and turtles. Molly dish fry should also have a good amount of oxygen from air bubbles coming up through the surface or powerful water pumps to provide aeration and circulation for respiration.

Make sure you maintain two inches or more of water depth at all times. Molly minnows are agile swimmers that need large amounts of space to move around freely. So they can’t survive in a too cramped environment with no room to swim. In addition, there should be enough food sources like algae and plants on the bottom and some floating vegetation near the top of the tank where molly fries spend most time patrolling for prey.

What Are The Risk Of Putting Molly Fry In Main Tank?

Molly fry is a fish fry that can survive in the main tank and be more suited for community tanks. In addition, they require less oxygen than adult Molly. So they’re able to have plenty of hiding spots where they don’t need to swim constantly.

It’s not a good idea to keep Molly fishes in your main tank because of the following reasons:

Change In Temperature

Molly fry can’t handle drastic changes in temperature like Molly adults. They’re able to withstand a range of 70-80 degrees Fahrenheit, but anything lower than that will kill them.

Molly Fry Eating Adult Molly

Molly fish are very aggressive hunters. They eat other fishes if they have no food source or hiding place from the adult Molly’s hunting an attack targeting them.

Fish Parasites Exploiting Weak Spot In Molly Fries Silk Tails

There is an opening on their tail fins where parasites can enter, leading to the death of mollies. In addition, it weakens their immune system making the parasite infection worse and more challenging for antibiotics to work against it.

Struggle For Food

Molly fries are more prone to starvation because they can’t swim around the tank as much. Molly adults will eat their food before it has a chance to reach Molly’s fry.

Gets Sick

Molly fry is more sensitive to diseases because they have a weaker immune system. As a result, Molly fish cannot survive in the main tank because adults will eat them, and there’s a risk of their fry getting sick. So it is when they can’t swim well.

Benefits Of Keeping Molly Fry In Main Tank

Despite these risks, there is the benefit of adding Molly fry in your main tank that includes:

Molly Fry Eating Adult Molly’s Food

Molly fry has no problem eating adult Molly’s leftover food. Therefore, you do not need to make special preparation of food for fry. Besides this, the fry also feeds upon live plants of the tank. Thus, they are easier to keep.

Lesser Work For You In Feeding Time

We don’t need to feed them as often because mollies eat everything you give them. Molly fry is more likely to get food because of the adult Molly’s hunting and attacking other fishes.

No Need To Get A New Tank

Molly fries can survive in freshwater or saltwater tanks. So, we don’t need to purchase a new tank once they grow up.

Safer For Any Other Fish In The Main Tank

Molly fry is less aggressive than Molly adults and won’t attack any other fish in the main tank if there aren’t enough hiding spots for them.

Molly Fry Are More Attractive Than Adult Molly

Some people may think mollies with tails look cuter than ones without them due to their appearance on TV ads that show young girls holding small guppies’ tails while feeding them.

How To Keep Molly Fry Safe In Main Tank?

But, there are still some ways you might be able to keep Molly fish fry alive while putting them into your main tank:

  • Provide plenty of hiding spots for Molly Fry, such as plants, rocks, or artificial objects that provide shelter from predators; this will also help reduce their need to swim constantly and burn precious energy.
  • Do not add Molly Fry when your main tank has ammonia or nitrate levels that are high; Molly Fry has a much higher sensitivity to ammonia and nitrates than other fish.
  • Feed Molly Fry food that floats on the bottom and sinks to the bottom when eating from it. This will help prevent accidents like fry sometimes attached to the filters. (which would decrease their chance for survival).
  • Ensure enough oxygen in the tank by adding different aquatic life like an air stone or plant roots submerged under gravel bedding.
  • Ensure that the pH level remains at its normal range (around neutral) by using an appropriate liquid solution or buffer
  • Keep Molly Fry in a tank with no other inhabitants that may eat them. It would help if you fed Molly fry at least two times a day provided nutritious foods such as brine shrimp and fresh vegetables.
  • Mollies are not small fish. So, when you keep their fry inside the main tank. There needs to be enough space for Molly Fry to grow and have room to thrive.

Some FAQs

What Is The Best Way To Keep Molly Fry?

There are many ways to keep Molly fry in the main tank. One way is by adding plenty of aquatic plants and hiding spots for Molly to fry hide from predators or other fish that may want a tasty snack.

Another good idea is to create small pits on the bottom of your tank. Molly fry will enjoy as they grow into more mature fish. Molly fry also enjoys climbing onto rocks, which can help keep them safe from other fish.

When Can You Introduce Molly Fry To Main tank?

It would help if you introduced Molly fry to the main tank only after they are half their adult size. The fry that is too small may not survive as other fish will eat them before Molly can get to them and protect her babies.

Molly fry also needs a lot of food. Thus, adding more plants or live feeder snails to their new home is an excellent idea to help Molly feed her growing fry.

How Does Molly Fry Eat-In Main Tank?

Molly fry should not eat any fish pellets or other types of food until they are at least half their actual size. Then, you can add live feeders like snails into the tank for them to snack on when Molly is busy feeding her big fry.

Molly fry will also eat algae and leftover food from the bottom of your tank as they grow into more mature fish. This can be a little messy, but it is worth it!

Is There A Point Where Molly Fry Can Survive In The Main Tank?

Molly fry may survive in the main tank after growing half. However, it is important to ensure that Molly has plenty of plants and other hiding spots for her fry before introducing them into the big fish tanks!

How Long Will Molly Fry Take To Grow Into Adult?

Molly fry will grow into Molly fish when you grow them about half. You should watch over the fry carefully at this stage. Also, make sure that there is enough food for them to eat, such as live feeders or lots of plants in the tank with Molly.

Is Molly Fry Easy To Keep?

Molly fries can be easy to keep if Molly takes the time to ensure that they have plenty of hiding spots and things to eat. However, Molly should also watch over her fry closely because she will not protect them from predators in other tanks!


Summing up, Molly fry is present in the wild. But you can rarely see them as pets because people think it’s too difficult to care for them. So they don’t require any particular food or lighting conditions. But it does need clean water (as it’s a plant-eater), Molly fry needs hiding spots.

Molly Fry can survive in your main tank if you provide them with enough aquatic plants, as well as some places to hide. However, Molly fish fry is vulnerable to any change in the water or tank environment.

If you have Molly Fry, it’s best not to put them into your main aquarium because it needs some special conditions. Also, it can be difficult for beginners who don’t know how much water changes Molly needs.

For any help caring for Molly’s fries, please get in touch with us. We’re happy to help.