Infusoria Definitive Guide

Published on February 7, 2017
Infusoria Definitive Guide

"Hey, Ernesto! My fish just laid hundreds of eggs! What should I feed the fry once they hatch? Something that's not too expensive but highly nutritious."

That's what the very first email I read about a year ago. John, who is the sender of the email, was a beginner, and that's an excellent question to start the day.

I then reply with a simple answer. "Why bother buying if you can culture your own fry's food?"

You who come to this page might have the same question as John. Good news is, this post will answer it. 🙂

Introducing... Infusoria.

Infusoria is a general term that refers to fish food or food for young fish which is grown or found in water.

Newly hatched fish or fry are often tiny and unable to feed on traditional fish foods such as pellets and flakes, which may be readily available in their environment.

Instead, the fry requires small, live or fresh foods to grow faster during their initial life stages. Infusoria is a popular solution because it offers these benefits.

This article will cover a general overview about infusoria, including their benefits in aquaculture and how to grow them at home.

Consider this review when culturing your infusoria at home.

How it works

During the first few weeks after hatching, the fry needs adequate nutrition to survive and develop into larger fish.

The real thing is.

Infusoria provides all the required nutrients and environment for the fry to develop.

Ok.. I know the definition of infusoria, but what is it truly?

Infusoria may include microscopic aquatic organisms such as plants and animals.

Some of the primary organisms you may find in infusoria include;

  • Paramecium
  • Algae
  • Stentor
  • Euglena
  • Vorticella
  • Amoebas
  • Rotifers

There are more than 2000 different species of infusoria which are available today. All of these types of infusoria are ideal for feeding your fry as they are tiny enough for the fry to eat after they hatch.

How to culture infusoria at home

how to culture infusoria Photo by Damian Vila

If you are planning to grow infusoria at home, you will need to learn how to culture them.

By knowing how to prepare them at home, you can ensure that you always have an adequate supply of fish fry food on hand; helping to save more money in the long run as you will you will not have to buy them from time to time. A good deal right?

A good deal right?

You can start preparing your infusoria by filtering debris from an established water tank.

Before you start, make sure to clean your plastic or glass tank to guarantee a healthy environment for preparing the fish food.

Then fill your container or jar with water from the planted tank or established aquarium.

When your tank is full, add some plant matters such as potato leaves, rice leaves, lettuce leaves or any other debris from an active filter.

Other materials you can use to grow your infusoria can include;

  • Milk
  • Yeast
  • Banana peels
  • Rabbit pellets
  • Straw
  • Grass
  • Liquifry

Leave your container in the sunlight for a few days, preferably 4 to 5 days to allow your culture to grow.

As the culture develops in the jar, the water will start to turn green or cloudy which indicates the growth of infusoria.

Now prepare to harvest your very first infusoria.

Feeding the fry

To feed your fry, add a small amount of water from the jar to your fry tank.

For easier feeding, harvest a small amount of infusoria from the pot using an eye dropper and squirt it directly in the reservoir where the fry is growing. As simple as that.

feeding fish with infusoria Image source

Remember that infusoria is microscopic-small. A little amount of water containing it is more than enough to feed your fry.

Please, please and please avoid adding too much infusoria to the fry tank at every given time because excessive infusoria will pollute your tank.

A good rule of thumb to remember is to add small amounts of infusoria in the tank at least twice every day to enable the fry to grow faster.

As time goes, you may realize that the water in the jar containing the infusoria may start to produce an unpleasant smell. Don't panic; this is entirely normal as decomposition of the organic matter is the reason behind it.

To minimize pollution of your fry tank, avoid adding any plant matter to the tank when feeding the fish.

However, with time, it may become difficult to distinguish the plant matter from the infusoria so you should discard old cultures after every 3 to 4 days and prepare fresh ones.

As your fry grows, they will become more tolerant to relatively larger fish feeds such as brine shrimp nauplii.

You can start introducing slightly larger foods during the second or third week after hatching.

You can add some infusoria as well when you are adding the new feeds.

Most people start offering larger foods by mixing them with infusoria.

BONUS: Raising your fry

If you intend to maintain a significant number of fry, you should consider providing them a safer environment, preferably in a separate tank where the adult fish will not get a chance to predate on the young fish.

While some fish may take care of their young ones after hatching, others will feed on them, reducing the size of your fry significantly.

Select a large tank to raise the fry independently, preferably a 10-gallon tank if you are starting.

Next, make sure the conditions in the fry tank are similar to those in the breeding tank.

As soon as your fish lay its eggs, collect and transfer the eggs into your fry tank.

infusoria for fish fry Image source

For easier cleaning, leave the bottom of your tank clear or bare, although you may decide to add some plant materials for the fry to shelter.

Use a sponge filter instead of a conventional, powerful filter to separate the eggs from other mechanical materials. Powerful filters may not allow the eggs to pass through it. Apart from offering the necessary filtration which is required, the sponge filters are also cheap to buy and easier to maintain, so they are ideal for this function.

As you feed your fry with new cultures every day, infusoria may accumulate in the rearing reservoir with time, causing pollution. The only solution is to carry out water changes from time to time.

Also, remember to feed your fry at least two or three times every day to enable them to develop quickly especially during their initial stages. If you feed them regularly, they should be able to attain at least 1 inch long after three to four weeks. Now you can transfer your fry into larger grow-out tanks.

Beware of pests like planaria worms, Cyclops, water tigers, Hydra, water boatmen and dragonfly nymph as well as other harmful organisms such viruses and bacteria entering to your fry tank. They can be as destructive as killing the majority of the fry.

If you handle it correctly, there is even a greater likelihood of producing a large fry. Consider using water from an established source, preferably an indoor resource to develop your culture.


Infusoria is an excellent food alternative for your fish fry. Besides it's totally free of cost, obviously you'll need energy and time to culture them, it provides the perfect nutrition for your fry.

Learn how to culture them, and you will get as much food source as you want, whenever you want. Don't forget to keep your infusoria cultures fresh all the time, as the older the culture is, the more organic matter it will bring.

Happy aquaculture-ing!

Featured image by Carl Guderian

One comment on “Infusoria Definitive Guide”

  1. hi Im naqib. recently Ive been trying to culture infusoria. I just wanted to ask, how do we know if the culture works? I mean, how do we know that the infusoria is cultured and we can feed the fry with it? like most articles on the internet said that we need to wait until the water turns clear, and by then we can already feed it to the fry. Right now I don't know when is the right time to give it to the fry, bcus the water doesnt even change its color. and during my fist try on culturing infusoria, I saw a tiny bits of moving organism inside the jar and it was a lot. But now, theres nothing but a cloady water and debris from the lettuce leaves that I put. Please help me, since my fry is afraid of Baby brine shrimp, and they wont eat it.
    Your feedback and reply is much appreciated.

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