How Long Does Molly Fry Take to Grow & Reach Full Size?
Has your female Molly given birth recently or is about to give birth then the next thing about to worry is fry care. You must be wondering that how long it will take your molly fry to grow? If you’re keen to observe your fry develop and know when these adorable tiny animals reach their full potential. Then you’ll have to wait a few months because it takes little time.
A molly fry typically grows better if protein-high diet is fed to it. Some claim that Molly achieves its maximum size in 3 or 4 months. But actually, it takes a bit more than this. Normally, it reaches to 1.5 to 2 inches in this time frame. But they reach full maturity in almost 6 months. At this point, the molly fish has developed scales and fins, and the females are even prepared for reproduction.

Meanwhile, make sure you’re taking good care of your molly fry, and if you’re not sure how you’ve come to the perfect place. In this blog, we will not only tell you how long it will take for the fry to develop to its full size but also how to care for it. Continue reading to ensure you don’t miss anything!
Molly Fish Growth Stages
After hatching, molly fish fry must be separated from their moms. This is due to the equal likelihood that adult mollies will eat their young. But they can’t stay in a separate tank indefinitely. At some time, but only after they have matured enough, you must reintroduce them to the common tank. But how long does it take for molly fish to mature? Depending on how you interpret “growing up,” the answer is:
1. Fry (Weeks 0-8)
When molly fish fry is hatched, they are still rather little. Their parents often consume them since their jaws are smaller than those of adult mollies. The idea behind separating them is to allow the fry enough time to develop so that adult mollies won’t mistake them for food.

It can take from a month to two months. The fry is now big enough to live in the main tank without being eaten by the adult fish. This stage may be distinguished by the fry’s independence from the yolk sac in terms of feeding.
After two weeks, you can transfer baby fish kept in breeding boxes to the main tank. Breeding crates are not very big. For more than fourteen days, you shouldn’t utilize them as a fish fry house.
2. A fingerling (Weeks 8-26)
Mollies are around 4.5 inches in length as adults. While the average Molly is 4.5 inches, some may grow to 6 inches. A molly fish may take four to six months to grow to this size. Although it has grown to its full size, it is not yet an adult.

The fish has functioning fins and completely formed scales by this point. Though certain mollies might take up to six months, keep that in mind. Some species of molly fish develop at even slower rates. For instance, it may take black mollies 10 months to attain their maximum size.
3. The act of reproducing (Weeks 26-52)
The mere fact that your fry has grown to its full size at four months does not indicate that it is prepared for mating. At six months, female mollies are mature enough to breed. However, you need to wait a year for male mollies. Therefore, it will take 52 weeks for the new generation to become fertile.

Newborn Molly Fry – How to Take Care?
To help your molly fry develop more quickly, follow these steps:
- Use a separate tank or a breeding box for the fry to reduce stress.
- Plants may be added to provide hiding spots.
- Put your aquarium in a peaceful spot.
- Keep the fry in a tank with a minimum capacity of 10 gallons.
- By supplying enough light, mimic the cycle of day and night.
- 72–84 degrees Fahrenheit should be the temperature setting for Mollies.
- Set the water’s pH for Mollies to 7.5 to 8.5 and its hardness to 20 to 30 dKH.
- Once every week, perform a partial water change.
- When feeding the fry, use baby brine shrimp, infusoria, and micro worms.
Due to uncontrollable circumstances like inbreeding and genetic flaws, some mollies will never attain their maximum size. If that doesn’t apply to your molly fish fry, though, then failing to create favorable circumstances in their aquarium can limit their growth.
In other words, creating ideal circumstances is the greatest strategy to promote development in molly fish fry. Typically, this includes the following:
1. Making a Calm Environment
Start by getting rid of the danger the parents pose. You have three choices to think about:
Separate Breeding Tank: Take the mother back to the main tank after giving birth. Until they are too big for the adult mollies in the main tank to consume, the fry can stay in the breeding tank.
Breeding Box: Include a breeding box if you don’t want to separate your fish. I utilize the Capetsma Fish Breeding Box myself (link to Amazon). Although the container is inside the main tank, it shields the fish inside from other fish in the surrounding water. Put the molly that is pregnant in the breeding box. Remove the mother after the baby is born.
Because you wouldn’t have to worry about introducing the pregnant molly fish to the circumstances in a brand-new tank if you relocated the mother to a different tank, many aquarists prefer the breeding box.
Plants: Keep the fry in the main tank, but add plants so they have places to hide from predators. Don’t count on all of your baby mollies to make it. Mollies can still locate them as adults. However, you may save enough money to increase the molly fish population in your aquarium.
In fact, it is inadequate to keep predators away from baby mollies. Additionally, you need to recognize and get rid of the different stressors that fish in tanks commonly experience, such as:
Avoid Noises: Not only the baby fish but even their parents would be disturbed by them. A female molly’s pregnancy may be complicated by loud, abrupt sounds.
Traffic: You should also stay away from areas where there are a lot of people, particularly if they continually stop to touch the tank walls.
Tank Size: They dislike being crowded, much like adult fish. Their tank should be larger the more fry you have. Here are my suggestions for fish tanks if you’re searching for a new one.

In other words, molly fish fry will stay little in a small tank and will develop to a large size in a large tank. However, that is untrue. Fish cannot regulate their size to meet the size of the tank. Having said that, a fry’s growth may be hampered by the stress of living in a confined tank.
Light: They require a regular light schedule, or 12 hours of daylight and 12 hours of darkness, to be more precise. It’s not necessary to have a completely divided lighting schedule. In other words, it’s not necessary to give the fish a certain amount.
The intention is to simulate the natural cycle of day and night they would encounter in the wild. Avoid very bright lights. You are also cautioned against abruptly turning on or off the lights. Change ought to take place gradually.
2. Environment Change at the Aquarium
Mollies won’t grow properly if their tank doesn’t contain a suitable environment. The following must be taken into account:
Check the temperature and pH of the parameters. Young mollies should be kept in tanks with a pH of 7.5–8.5 and a temperature range of 72–84 degrees F. The water should also be between 20 and 30 KH hard. To monitor the parameters, use a thermometer and testing supplies. Don’t let them stray from the area your fry need.
Filtration: The water will be maintained free of pollutants. Fry may still use foam filters even when there are better ones. A stronger filtration system has an equal chance of luring the fry in. It could also stress them out by generating a stronger current than they would want.
Aeration: Young mollies are more vulnerable to an oxygen shortage than adult mollies are. This necessitates maintaining aeration in their tank. A decent filter will ensure even oxygen distribution in the tank, but you may increase its effectiveness by adding one or more air stones. In my tank, I make use of the Hygger Aquarium Air Stone.
Plants: They generate oxygen and ingest carbon monoxide when light is present. However, you should be aware that this process reverses in the dark, so you must pay particular attention to tanks in areas where there is a lot of darkness. In particular, if there are too many plants, they will decrease oxygen levels rather than increase them.
3. Maintaining Equipment Frequently
Are you properly maintaining your tank? If not, the unclean surroundings could prevent your fry from growing normally. Once or twice a week, you must perform partial water changes. As a result, the amount of ammonia, nitrates, and nitrites in the tank will decrease and contaminants will be removed.

Use water conditioners to remove contaminants from the water. It’s also crucial to occasionally scrub the tank’s walls and contents. Rinse them well to avoid contaminating your fish with detergent residue. Your molly fish fry will develop at the proper rate if the tank is kept clean.
4. Giving Your Fry Enough to Eat
Some aquarists make the error of giving their fry-only foods high in protein. They act in this way because protein usually promotes development. But because it leads to vitamin deficiencies, this is a risky practice that seldom yields the outcomes individuals hope for. Long-term, you will harm your young mollies’ health.

Baby brine shrimp, brine shrimp eggs, infusoria to vinegar eels, and micro worms are all necessary components of a well-balanced diet for molly fish fry. They need to be fed four to five times every day. They need a lot of nourishment for their bodies.
What Should Be Done When Molly Fries Are Full Size?
Move your molly fry to the main tank if they are big enough to survive without their parents consuming them. But try to keep them out of the water. The changeover should be handled carefully and gradually. If not, it could lead to conflict between the fry and aquarium fish.
Related Post: Can Mollies Live With Goldfish?
How to Set Up Your Home Aquarium for Your Molly Fry?
Before adding molly fish to your home aquarium, you must be aware of the proper maintenance procedures. Additionally, the level of care you offer your molly fish might affect how well and how quickly they develop.
Separate the Mother Molly
When the mother is just about to give birth in a communal tank, you should remove her to safeguard the survival of your molly fry. Additionally, adult mollies, particularly males, often prey on juvenile mollies. Additionally, if the mother’s abdomen is enlarged or the area adjacent to her anal fin has darkened, you will know she is about to give birth.
The length of time needed to put the fry in its home
Make sure it doesn’t take too long before you put your fry in its new habitat, whether you bought it from a fish store or a breeder. Additionally, if your adult molly gives birth, it shouldn’t be long until you move the fry into its new habitat. Additionally, the vehicle should be a huge plastic fish bag filled with warm water. To reduce stress, make sure you move quickly to get them settled in the new house.
Prepare the fry
Before placing the fry in the nursery tank, acclimating them is crucial. Additionally, this will lessen the likelihood that the fish may be shocked to death. Additionally, acclimatization is carried out by putting the fish bag on top of the aquarium tank.

Additionally, give the bag at least 15 minutes to float. This aids in adjusting the bag water’s temperature to the nursery tank’s temperature. The fry is then released from the bag by being allowed to swim freely into the nursery tank.
The Bottom Line On How Long Does Molly Fry Take to Grow & Reach Full Size?
Young fry has already been detached from the yolk sac and is ready to feed on its own if your molly has recently given birth to them. They will still take up to 26 weeks to attain their full size at this stage. At this stage, the females are likewise sexually mature. The male fry won’t be able to procreate for another six months. By maintaining a calm atmosphere and changing the water’s properties, you may encourage the growth of the neonates. For good fries, routine maintenance is also essential.