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Molly Fry Food 101: What Do They Eat, How Often, & More

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When I first had to deal with molly fry, the first question that popped into my mind was what to feed them. I didn’t know if I could use the same food adults eat and how often and when I should feed the fry.

Here is a table summarizing what molly fry typically eat, depending on their age:

The Food TypeAt What Age
InfusoriaUntil day 7
Baby brine shrimpBetween days 7 and 21
Freeze-dried/frozen foodsDay 21 and beyond
WormsFrom week 5 and beyond
Flakes/pelletsFrom week 8 and beyond

As we move forward, I will discuss the different types of food molly fry can eat and include my personal recommendations. Then, I will elaborate on how often and how much you should feed them.

A molly fry nursery containing about 100 fry.

Still curious? Feel free to check my complete guide on molly fry. There, I discussed how to care for molly fry, what they eat, how often to feed them, their growth stages, and much more.

What Do Molly Fry Eat?

Mollies are omnivores that eat animal and plant matter. Their babies are no different. You should give them a mix of the following:

1. Infusoria (Days 1-7)

The term refers to various microorganisms, including paramecium, daphnia, and protozoans. The food item appeals to fish because of its size and nutritional value.

Newborn mollies are small, so it is good practice to feed them microscopic foods, which is where infusoria enters the picture.

You can create infusoria in a container using banana peels, milk, straw, lettuce, and the like.[1]

Molly fry should be fed on infusoria until they are seven days old. From that point, this type of food will be too small for them. An excellent choice after that would be baby brine shrimp.

  • If you’ve never made infusoria before, here is an excellent video that will walk you through it:

2. Baby Brine Shrimp (Days 7-21)

Baby brine shrimp is the perfect food for baby mollies, boasting proteins (71%), lipids (30%), and carbs (23%).[2] You can use this type of food until week three.

You will be hard-pressed to find a more nutritious food source for growing fish. Aquarists tend to freeze the brine shrimp to combat bacteria and parasites.

If this option resonates with you, I suggest checking the Ocean Nutrition Instant Baby Brine Shrimp (link to Amazon). Each jar contains roughly 1.5 million nutritious baby brine shrimp.

3. Freeze-Dried & Frozen Foods (From Day 21)

You can keep feeding your molly fry baby brine shrimp until they are three weeks old. From that point, you can start using freeze-dried or frozen foods like bloodworms and daphnia.

A good choice would be the Hikari Bio-Pure Freeze Dried Blood Worms (link to Amazon). I used that in my molly fry tank, and they absolutely loved it.

A suitable addition to freeze-dried foods would be vegetables like zucchini. They provide a reliable and consistent source of nutrition, and baby fish can graze on them all day long.

One week-old molly fry, searching for food.

4. Worms (From Week 5)

Worms are probably the most popular food option among aquarists. That includes bloodworms, earthworms, white worms, grindal worms, and more.

Tubifex worms are controversial because they can introduce diseases to the water.[3] Approach them cautiously.

5. Flakes & Pellets (From Week 8)

Flakes and pellets have a poor reputation in some circles. Aquarists tend to dismiss them as dangerous or not as effective as live foods.

And in truth, if you have the option, you should give the baby mollies live foods. But flakes and pellets are a decent alternative.

The key is to secure high-quality products with a high protein content, preferably flakes and pellets made with young mollies in mind. The correct flake food will give molly fry all the nutritional elements they need and improve their colors.

I personally recommend getting the Fluval Bug Bites Flakes (link to Amazon). These are made of fly larvae and contain a large amount of protein.

Do I Have To Change The Molly Fry Diet?

As I discussed above, you can use different kinds of foods depending on your baby molly’s age. However, that isn’t mandatory. It’s merely a recommendation.

Many fish owners feed their molly fry the same type of food from day one until they are adults. That is perfectly fine.

But from my experience, mixing at least two types of food is always better. This way, there is a higher chance the fish will get the protein, carbs, and vitamins they need.

If you do wish to use the same food, make sure you adjust its size. For example, you must grind the pellets thoroughly when the fry are young. Otherwise, they won’t be able to eat it:

When And How Often To Feed Molly Fry?

You can start feeding molly fry the moment they are born. Fish in the wild eat at dusk and dawn. But that doesn’t apply to omnivores or herbivores because they spend the entire day looking for food.[4]

Molly fry are omnivores. Additionally, their bodies have short digestion cycles. Therefore, they require frequent feedings, possibly five or more.

You should sprinkle food into the tank every few hours. The exact time doesn’t really matter. You can select any hour of the day that suits you.

The key is to maintain consistency. Feed the babies at the same time every day. Eventually, they will adapt to your schedule, rising to the surface in anticipation of the food during mealtimes.

I also suggest keeping the meals small. Aim for quantities they can consume in five minutes or less. Don’t forget: the babies must eat five or more times a day.

Even though they have voracious appetites, their bodies are still small. Therefore, overfeeding is more likely to chock the water with leftovers.

You have to provide meals in sufficient quantities without going overboard, a balance many aquarists struggle to find, which is why some own automatic feeders.

Admittedly, overfeeding is not a problem if you have a regular maintenance routine that includes water changes.

A molly fish fry, looking for food on driftwood.

How Much Should I Feed Molly Fry?

Because molly fry are tiny, the size of their food matters; you have to grind the meat and vegetables into pieces small enough to fit their mouths.

However, even though their bodies are so tiny, baby mollies eat a lot because they are growing. They have extensive nutritional needs.

They only need a pinch of food each time. But you must add that pinch several times a day to satisfy the creatures.

The exact amount will depend on the number of fish. As I previously discussed, molly fish can have up to 100 fry in a single batch.

Some aquarists will only add food in quantities the babies can finish in two minutes. Others will stretch that duration to five minutes.

Professional aquarists have not provided any definitive rules for newcomers to follow where the quantity of food is concerned. You have to experiment.

Start by making an educated guess. Add an amount that seems fitting and observe the results. If the water has more leftovers than expected, you gave the babies too much food. Cut back on the volume.

If the babies finished the food too quickly, you did not give them enough. Keep trying and adjusting until you find a suitable answer.

Lots of small, newborn fish in a glass jar

Do Molly Fry Eat Algae?

Yes, molly fry eat algae. Many aquarists treat algae as a nuisance, and for a good reason. However, algae have nutritional value, which is why some communities use them as an alternative to fishmeal.

Fishmeal appeals to aquarists because it has all the high-quality proteins and essential amino acids fish require. But you can find large quantities of essential amino acids in microalgae, not to mention taurine and lipids.[5]

A paper from the Organization For Protection of Eco-System, Environment and Endangered Species cited situations in which fish farmers used algae to improve the colors of ornamental fish – Algae are sources of carotenoid, lutein, and other pigments.[6]

Therefore, not only do baby mollies eat algae, but they have a good reason to do so. They will also feed on whatever matter falls from the plants in the tank.

They will gravitate towards green, black beard, and hair algae. They can also eat blue-green and brown algae.[7] Adult mollies can survive for up to two weeks without food if their tank has plants and algae.

However, baby mollies are not quite as lucky as they need regular meals. And even then, about half of them won’t survive.

Even if you have a sizable population of baby mollies, you can’t trust them to control the algae infestation in your aquarium. That being said, algae are a decent alternative for aquariums that don’t have enough food.

A review from the Fisheries and Aquaculture Department of the Food and Agriculture Organization of the United Nations found that algae played a significant role as a food source in small-scale aquaculture.[8]

Therefore, you’re not wrong in using algae as an alternative food source. But if you have a heavy infestation, you should take additional steps to control the algae outbreak, especially if the baby mollies have shown that they can’t eat enough to control the algae.

A molly fish fry, eating algae that have grown on a plant.

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Conclusions

Molly fry can eat many types of food, including infusoria, baby brine shrimp, flakes, pellets, and worms. You can stick with one type if it is nutritious enough (except infusoria, which shouldn’t be used after day seven).

Also, it is essential to adjust the food size to the fish’s mouth. For example, you must grind pellets properly if the fry are still small, or they won’t be able to eat them.

Molly fry should be fed approximately five times a day. After week four, I would lower it to three times a day, and after two months, to two times a day.

References

  1. https://www.thesprucepets.com/what-is-infusoria-1379895
  2. https://en.wikipedia.org/wiki/Aquaculture_of_brine_shrimp
  3. https://www.thesprucepets.com/feeding-live-foods-1380910
  4. https://www.aqueon.com/articles/how-to-properly-feed-your-fish
  5. https://thefishsite.com/articles/the-use-of-algae-in-fish-feeds-as-alternatives-to-fishmeal
  6. https://www.researchgate.net/publication/309647394_Algae_in_nutrition_and_colouration_of_ornamental_fish_A_review
  7. https://aquariumstoredepot.com/blogs/news/molly-fish
  8. https://www.fao.org/3/i1141e/i1141e.pdf