How To Care For Molly Fry? [Step by Step Guide]

If you see your Mollies breeding often, then brace yourself for looking after their Molly fry sooner. Since Molly fish ends up abandoning or harming their babies after their birth, it all comes down to you to nurture them for their healthy survival. But do you know how to care for Molly fry well?

You can care for Molly fry by ensuring their protection in the main tank, maintaining a separate nursery tank, feeding them rightly, and preventing serious fish diseases. Besides, keeping tank habitat clean, accurate water temperature, lighting, and other necessity required for them also make under the list of Molly fry care.

This is important to care about molly fish fry as molly fish are livebearers and the fry are way more delicate. You have to read the entire article below to know more about molly fish fry care.

Molly Fry Birth

I think you are aware that Molly fish are livebearing fish. Meaning they give birth to their babies directly instead of egg-laying.

So, after mating for a single time, the female Mollies store the sperm from males for a specific period.

They then fertilize the eggs inside them and produce. Later, after a couple of weeks, they give birth to the Molly fry.

Here, remarking on the gestation period of Molly fish is significant to identify the Molly fry’s birth.

However, this period may not be the same for all pregnant Mollies. Yet, you can determine it with an average gestation period defined for Mollies in general, which is 45 to 50 days.

How To Care For Molly Fry?

Step 1: Large Tank Size

You may be perplexed to know the tank size analysis requirement even for the Molly fry. But yes, it is indeed essential! 

You can get a tank size ranging from 10 to 20 gallons. After that, they require enough tank space, live plants, and aquarium equipment to balance the tank environment.

While fulfilling these aspects, tank size is crucial for the Molly fry to grow and endure wholesomely.

Besides, not to forget, Mollies give birth to many Molly fry at once. So the birth counts may reach 100 too. So, the tank must be large enough to hold many Molly fry while providing a comfortable experience.

So, although you will be keeping tiny Molly fry, a large tank size ranging from 10 to 20 gallons is essential for them.

Step 2: Filtration

A decent filtration system is essential for the molly tank, especially your fry. Thus, filtration installation is vital for them in a separate nursery tank.

You can set up a simple foam filter or any similar filtration system by analyzing the tank size. Ensure the chosen filter doesn’t pull and suck Molly fry inside it. The device must be safe for them.

If you are unsure about filtration safety, you can buy a fitting or an attachment from your local aquarium store and fix it.

Or, you can modify filtration by pulling a small nylon layer over the filter and fastening it with a rubber band.

After maintaining a proper aquarium filter in the nursery tank for Molly fry, the water quality and cleanliness balance, you can help your molly fry live a long and happy life. However, remember that your molly fish fry cannot survive without a filter if the water quality is zero.

Step 3: Water Temperature

Mollies typically are tropical fish. Thus, it is essential even for Molly fry to get the warm temperature in their tank.

So, maintain the ideal water temperature for molly fish fry at 72 to 84 degrees Fahrenheit (23 to 28 degrees Celsius). This water warmth will boost Molly Fry’s metabolism to eat correctly and grow finely.

I suggest you get a suitable aquarium heater to keep the water temperature consistent and precise. Also, you can use an aquarium thermometer to analyze the correct water temperature running in the tank currently. 

Step 4: Adding Plants

For adding plants to the tank, you can go for either artificial or live ones. The only thing you must note and perform is to add plants before you put Molly fry in the tank. Also, remember your molly fish do not prefer a densely planted tank, and neither does their fry.

While searching for a suitable aquarium plant, I advise you get a mix of broad-leafed plants like Java Moss, Java Fern, and grasses. It makes the best hiding spots for your Molly fry.

Moreover, you can add some floating plants, which are helpful for newborns as it provides a space nearer to the surface to hide instantly after birth. 

Step 5: Lighting

Lighting is also an important part to look for while maintaining a separate tank for Molly fry. Suitable lighting in the tank secures their healthy growth. 

You must ensure 12-14 hours of tank lighting in a day and the remaining hours of darkness to let your Molly fry rest. 

Don’t overlight the tank for more than 14 hours in a day. It will affect the resting schedule of your Molly fry.

Step 6: Feeding Molly Fry

The moment after your Molly fry is born or gets into the nursery tank comfortably, feeding them a healthy diet is significant. It contributes to their healthier and more active growth.

Feeding them is not troublesome as they don’t require a specific diet plan but high-quality and fresh food.

You can offer adult Mollies’ food to the Molly Fry but in a crushed powder form. It makes them easy to eat food and digest it properly as their mouth is tinier than a general Mollies.

Offer some live foods like baby daphnia, brine shrimp, vinegar eels, blood worms, etc., to your Molly fry. If not live food, frozen or freeze-dries diet option is also appropriate. 

You can also get some available fish food for feeding small fry. I suggest you purchase Hikari First Bites for your Molly fry because this food includes every element required for baby fish.

Not to forget to clean the leftover food from the tank immediately to prevent the tank from getting foul. To clean up, use a skimmer or a net. 

How Many Times A Day Can I Feed Molly Fry?

Since your Molly fry is small, their digestion cycle would also last for a short time. Due to this, they are likely to get ready to eat another meal soon. 

So, you can aim to feed them in a small amount at least five times a day. Although they get ready to eat usually, avoid overfeeding them. 

Step 7: Preventing Molly Fry From Fish Disease

Since your Molly fry will be tiny to even realize and fight against any fish disease, it is better to prevent it. 

If you are unaware, realize that the air consists of various microorganisms that can harm your Molly fry when the aeration in water occurs.

Some bacteria and parasites are already present in the tank water, which increases the chance of fish disease in Molly fry. 

Thus, conditions like these can affect Molly’s fry when it gets extreme and left untreated as they have less immunity to fight against it.

So, to prevent Molly fry from fish disease, here are some ways to go through:

Regular Water Change

Your molly fish requires a regular water change, and so does your molly fish fry. Water change in the tank usually improves the water quality by reducing water filth and providing fresh and qualitative water to Molly fry. 

Perform 20% to 25% water change in the Molly fry tank daily. It helps to keep the toxic levels low and restore the water quality. It then contributes to the healthier growth process of fry.

Do not overdo the water change in the aquarium. With regular water change, the toxicity in the tank water reduces. In addition, it keeps your Molly fry safe as it somehow prevents the likely diseases. 

Be careful; you should not use tap water while changing the tank water, as tap water is harmful to your aquarium fish

Maintaining Tank Hygiene

A hygienic tank environment is what your Molly fry requires to grow rapidly and healthily. Not only this, but it also prevents your fry from various fish diseases once the tank gets wholesome. 

You can keep the tank clean and fresh by removing dead leaves or plant parts, leftover fish diets, fish excretes, and other irrelevant elements found.

To clean the debris, you may use a net or skimmer.  Also, keep the filtration mode on to ensure the water quality in the tank is optimum and fresh

Saving The Molly Fry Is Essential. Know Why?

Unlike other fish, you will lack to witness the nurture of Molly fry done by their parent Mollies.

They are likely to harm their baby Mollies after their birth. Thus, the first task you shall perform while caring for the Molly fry is to protect them.

Molly fry is unsafe not only with their parent Mollies but with every fish in the community tank.

As these Molly fry are tinier after their birth, most of the other species in the tank tend to chase and munch them.

As a result, Molly fry becomes a tasty snack for other fish, including their parents, when you don’t save them.  Hence, it is significant to save this Molly fry to see them growing and living pleasantly in the aquarium.

Methods To Protect Molly Fry In The Main Tank

As I have mentioned before, Molly fry is at risk from non-other than their parents. Thus, it is significant to save them if you wish to see them grow into an adult, healthy Molly.

You can select some methods to protect and care for Molly fry. The methods are:

Breeding Box Installation

Installing a breeding box in the main tank will help you isolate the Mother Molly and eventually Molly fry from the rest of the fish species. It is one of the best options to separate and save the Molly fries after birth. 

A breeding box is a container made to protect the expecting Molly or mating fish by providing separate space in the tank.

The tank water runs through a water pump in this box without troubling the fish inside it. So, your fish will certainly have no problem surviving in the box. 

Pick the pregnant Molly fish and keep it in the breeding box till she gives birth. Then, you can keep her in the main tank without allowing any of the other tank mates to trouble her. 

Once she gives birth to the Molly fry, the babies will fall into another section of the breeding box, leaving the mother Molly behind. 

You can then keep mother Molly back in the main tank while Molly fry into the breeding box.

Hiding Spots

Another method you can protect and care for the Molly fry in the main tank is by maintaining enough hiding spots for them. Don’t you know how much molly fish loves to hide in the tank? Well, their babies aren’t that different after all.

You can keep the baby Mollies apart from other fish by hiding spots like artificial plants, live plants, and other aquarium decorations. 

However, this method may not be effective as a breeding box set up after the birth of Molly fry. They are unlikely to last long as other fish will attack and eat them once they are noticeable. In addition, they instantly.

If you are unsure of hiding spots, you can consider keeping them in a separate tank box.

Is A Separate Nursery Tank For Molly Fry Necessary?

Since you must save Molly fry from the rest of the other species in the main tank, fixing a separate nursery tank for them can be beneficial.

You know your molly fish eat their babies, right? Hence, you cannot keep your Molly fry even with their mother Molly in a mutual tank. If put together, your Molly fry has less chance to survive in the main tank as their mother is likely to chase and eat them. 

Thus, a separate nursery tank for Molly fry is necessary to separate them from their mother Molly immediately after their birth.

A nursery tank is where Molly fry wholesomely nurtures until they start growing. Here, they are pretty safe as there will be no fish threat. In addition, this tank will protect them before they become a tasty snack for others. 

However, there are various elements to look for while you equip a separate tank for your Molly fry. Such factors are necessary to secure the lives of Molly fry in an aquarium.

How To Care For Molly Fry

Introducing Molly Fry In The Nursery Tank

After maintaining every requisite element in the nursery tank, you shall carefully introduce your Molly fry into it.

Introducing them in the tank is a precise task as getting into a new environment may perplex Molly fry a little. In between this, they may stress out if you put all of them suddenly in the tank.

So, to avoid such disturbance, let the Molly Fry containing bag or breeding box sit and float in the tank water for at least 15 minutes.

It will slowly make the temperature inside the bag or box equivalent to the tank water temperature.

After 15 minutes, slowly release all the Molly Fry and allow some time to let them swim. Then, observe if they all adapt and swim well or not.

Once the Molly fry settles and starts swimming, understand that they got comfortable and introduced well in the nursery tank.

However, if you see any of them finding space to hide, know that Molly fry felt uneasy and nervous.

In such a situation, use a net, quickly remove the fish from the aquarium, and keep it back in the same bag or breeding box again. 

Later, carefully repeat the process but don’t exercise too often. 

When To Transfer Molly Fry Into The Main Tank?

Keeping Molly fry in a separate nursery tank is the best way you can save them and rise. But there comes a time when you must transfer them into the main tank.

So, you can transfer Molly fry into the main tank after keeping them in a nursery tank for two to three weeks.

At this point, they usually start growing and reach the length where other fish may not confuse them as a snack.

Thus, after keeping Molly fry in a separate tank for 14 to 21 days, you can see them growing large enough to settle in the main tank without any hazard. 

Does Molly Eat Their Babies?

Yes, Molly eats their babies if they share the same aquarium. Being a parent, it looks strange to eat their baby. But in the case of Molly fish, this happening is not an unusual thing!

Mollies usually eat every tiny element that fits inside their mouth. Here, the Molly fry size is fit to get inside Mollies’ mouth, which puts them at risk if they share a mutual tank.

Once the Mollies notice Molly fry’s moment, they will likely chase and munch them instantly. So, even if the Molly fry is their baby, the Molly fish will start nipping them after birth.

Frequently Asked Questions

I have also collected some of the frequently asked questions and answered them for you to help you take care of your molly fish in the tank.

Do Mollies Give Birth To All Fry At Once?

Despite being small-sized fish, Mollies give birth to all fry at once. A female Molly usually produces multiple births, around 100 at once.

Can I Keep Molly Fry In A Fishbowl?

No, you cannot keep Molly fry in a fishbowl. A fishbowl is too small to fit every requisite necessary for them, like filtration, hiding spots, aquarium heater, etc.


From separating them from the main tank to nurturing them well in another tank, these aspects are essential to care for Molly fry. Also, feeding them a healthy diet and preventing them from the fish disease are crucial things you shall be aware of while looking after them.

However, you need not worry about your Molly fry once you understand everything about their care. 

Remember, you will be the only one who saves them after birth from their parents and other fish species.

Therefore, keep your Molly fry safe and healthy!