Unusual Betta Fish Food (Vinegar Eels & Worms)

by Kevin

Foods for baby betta fish and aquarium fish fry.

Growing your live food cultures for betta fish is not difficult.

Usually, all you need is a small container and some substrate or bedding to reproduce the worms or nematodes you plan to feed your fish,.

Other cultures like vinegar eels need vinegar (not surprisingly).

These cultures can provide a cheap and nutritious addition to your fish’s diet.

Many types of live fish foods can be cultured at home, but this article is about 3 live foods in particular that I find to be some of the easiest to produce at home.

Two of these live cultures are particularly good for baby betta fish (betta fry) and other aquarium fish fry.

One of the foods is excellent for feeding young betta fish and also conditioning adult betta fish for breeding.

1) Vinegar Eels

Vinegar eels for aquarium fish.
Vinegar eels gathering in branching colonies.

What are Vinegar Eels?

Vinegar eels (Turbatrix aceti) are actually nematodes (not eels); the way they wiggle likely reminded someone of eels.

Anecdotally, these little nematodes were a headache for wine makers, who attempted to strain them out of fermented grape juice.

Vinegar eels reach about 1/16 of an inch (2mm), making them an ideal live food and an excellent source of protein for baby fish.

Are Vinegar Eels Harmful to Humans?

Vinegar eels are not harmful to humans, and are likely consumed by accident by some people who buy unfiltered apple cider vinegar and leave it sitting in a cabinet for a few months.

Despite being safe for humans, manufacturers of vinegar are required to strain and pasteurize their vinegar products before selling to consumers, so don’t lose sleep over the idea of eating these nematodes.

What Do Vinegar Eels Eat

Vinegar eels feed on the bacteria and other microorganisms found in unfiltered vinegar, like apple cider vinegar.

How to Culture Vinegar Eels

The easiest way to acquire a vinegar eel starter culture is to find another aquarist who already has a vinegar eel culture.

I purchased my vinegar eel culture at my local aquarium club during a club auction.

Leaving unfiltered apple cider vinegar with apple slices out on a counter for a few weeks may produce an eel culture naturally, but finding someone who already has an eel culture is much faster.

Keeping Vinegar Eels

Vinegar eels are simple to keep.

1) Grab a mason jar or some other container (about 2 quarts).

2) Add your vinegar eel starter culture to the new container, ideally with a solution of half apple cider vinegar and half de-chlorinated water.

3) Add 3-4 apple slices.

4) Cover the container with breathable cloth and store at room temperature away from the sun.

The vinegar solution will become cloudy as the eels propagate.

How Long Do Vinegar Eel Cultures Last

Your new eel culture should last 4-6 months.

Maintenance is minimal; just add water and vinegar when appropriate to counteract evaporation.

Creating new vinegar eel cultures around month 4 and cleaning out the old cultures around month 6 will help you maintain a healthy cycle of vinegar eels.

Feeding Vinegar Eels

You probably thought the apple slices were for the vinegar eels, but these tiny nematodes actually feed off of the bacteria that break down the apple slices.

Apple slices break down slowly in vinegar and 3-4 slices should last a few months.

How to Harvest Vinegar Eels

Harvesting vinegar eels can be tricky because you do not want to dump apple cider vinegar into your aquarium.

One of the easier ways to harvest vinegar eels is to find a container with a long neck and pour some of your culture into that container.

Next, place some filter floss material in the neck of the container and fill the top portion of the container’s neck with fresh water.

The vinegar eels will travel through the filter media into the fresh water to reach the surface.

Now that the eels are in freshwater, you can collect them with a turkey baster and feed them to your fish.

The video below shows a quick and easy method for harvesting vinegar eels:

2) Walter Worms

What are Walter Worms?

Walter worms, Panagrellus Silusioides, like vinegar eels, are actually nematodes rather than worms.

But these creatures wiggle like worms and aquarium fish love them.

Walter worms are tiny, about 1/16 of an inch on average.

Like vinegar eels, Walter worms make ideal food for fish fry that are unable to consume larger prey like baby brine shrimp.

Walter worms are nonparasitic and live off of yeast and bacteria.

How to Culture Walter Worms

Walter worm culture for aquarium fish.
Small walter worm culture.

You can order a culture of Walter worms online or find someone at your local fish club who is breeding them.

Walter worms like to be kept at a room temperature between 65 F and 80 F.

Higher temperature will produce these nematodes more quickly but lower temperatures will help the culture last longer.

You Will Need:

1) a small plastic container, like a deli container;

2) food for your worms

Feeding Walter Worms

Walter worms eat bacteria and yeast, so providing a place for those to grow is essential.

Ideal recipes include:

1) Baking yeast and oatmeal: Cook oatmeal until a pasty consistency. Add bakers yeast. Let cool.

Put the oatmeal/yeast paste into a deli container.

And spread your Walter worm culture on top of the paste.

Put a lid on the container and poke tiny hole with a needle or other small object.

2) Baking yeast and cornmeal: Same process, cook until a pasty consistency.

Let cool and place the paste into a plastic container.

Add the Walter worms to the top of the paste.

Put a lid on it and poke tiny holes into the lid for ventilation.

Harvesting Walter Worms

You will notice your Walter worm culture flourishing when they begin crawling up the walls of the container.

Removing Walter worms for feeding can be done with a small paintbrush or just your finger.

3) Baby Brine Shrimp

What are Baby Brine Shrimp?

Baby brine shrimp are the larval stage of brine shrimp, which live in the ocean.

Many betta breeders swear by baby brine shrimp as the best live food, hands down, for betta fish that have just hatched.

Betta fry tend to be healthier and more fry seem to survive compared to fry that are only fed foods like vinegar eels.

How to Culture Baby Brine Shrimp

Culturing and hatching baby brine shrimp involves buying brine shrimp eggs, setting up a hatchery, and providing the right conditions for them to hatch.

The video below provides an excellent DIY method for hatching baby brine shrimp for your aquarium fish:

4) White Worms

What are White Worms?

“White worms” is a general description for a variety of small, pale worms.

The type of white worms that make great fish food are actually a white worm used in aquaculture: Enchytraeus albidus .

The Soviet Union cultured these white worms at a large scale to feed Sturgeon fish cultures, because white worms were easy to cultivate and cheap to house and maintain.

White worms are actually large enough to feed adult betta fish and are probably most suited for the juvenile betta fish rather than newly hatched fish.

White worms tend to be safer for your fish than feeding aquatic worms like bloodworms and black worms, which are prone to parasites.

White worms are highly nutritious, being 49%-69% protein, 10%-27% lipids, and 5%-8% ash.

How to Culture White Worms

In general, you want moist, but not wet, substrate for your white worm culture and a room temperature between 60 F and 75 F.

You will need:

1) A Container

A plastic box the size of a shoebox works well for white worms.

The translucent plastic will allow you to keep an eye on your white worm colony.

Some aquarists prefer to culture white worms in a wooden box.

The downside is you won’t be able to see your white worm culture without digging them up, but the benefit is that the wood will absorb excess moisture that plastic containers cannot.

White worms prefer cooler temperatures but they do fine at room temperature in many areas.

I find that white worms thrive best below 70 degrees Fahrenheit but seem be fine up to around 78 degrees Fahrenheit.

2) Substrate

Both potting soil and coconut fiber substrate work well for white worms.

White worms prefer moist substrate but not soaking wet.

A few squirts from a spray bottle every week or two is adequate moisture.

The video below also provides a helpful explanation of how to culture white worms:

Feeding White Worms

White worms will eat almost anything you have laying around in your kitchen; coffee grounds, stale bread, and cat food all make excellent white worm food.

Avoid feeding meat products to your white worms as meat tends to attract flies and produces nasty smells while decomposing.

My favorite food for white worms is dry cat food.

Simply put a piece or two— depending on the size of your white worm culture— into the container and monitor how quickly the food disappears.

If the food becomes covered in mold, remove it and feed less. You want to find the amount of food your white worms can consume in a week without mold taking over.

Healthy White Worm Culture

Healthy white worms live about 8-9 months and produce over a thousands eggs during their lifespan.

Once your white worm culture becomes a dense mass of worms, you will want to harvest the excess worms or create an additional culture to maintain optimal conditions for your worms.

Harvesting White Worms

Use a pair of tweezers to pick up a juicy white worm and then dip it in a bowl of water to remove any debris.

Then drop the worm into your aquarium and watch your fish go crazy.

White worms can also be removed with your finger and dropped into your tank.


Having a ready supply of live food for fish fry is essential if you plan to breed aquarium fish.

Vinegar eels, walter worms, and baby brine shrimp are ideal starter foods for betta fish fry.

Out of the three live foods mentioned above, white worms are perhaps the most versatile because they can be fed to a variety of fish at different life stages, including adult betta fish.

Culturing live foods for aquarium fish is easier than you think, and provides a cheap and quick supply of nutritious food for you fish.

As always, stay zen aquarists.