How to Culture Vinegar Eels For Fish Fry

How to Culture Vinegar Eels for Fish Fry

Do you want to get into fish breeding, but don’t know how to feed tiny fry too small to eat regular food? Try vinegar eels! This live food can be cultured quickly and is ideal for raising babies until they are old enough that they can eat baby brine shrimp.


What are Vinegar Eels?

Vinegar eels, which are either white roundworms (or nematodes) that feed on microorganisms found in vinegar and fermented beverages, are harmless. They are small and easy to grow, measuring in at 50 microns in size and 1 to 2mm in length. They are often fed to baby brine shrimp, killifish, rainbowfish and other fry that need tiny foods.

Vinegar-eels also have other benefits that make them great for feeding fish fry. Unlike banana worms and other micro worms, they can survive for several days in fresh water, they swim around in the water column instead of sinking straight to the bottom, and their wiggling motions entice babies to eat more and grow faster. Although vinegar eels may not be as nutritious as baby salt shrimp, which are born with thick yolk sacs, they are still a great food source until the fry are large enough to eat baby salt shrimp.

How can you start a vinegar eel culture?

1. These materials should be collected:

– Starter culture of vinegar eels (from local fish auctions or online sources like – 1 container with a long neck (like a wine bottle) – 1 backup container (like a 2-liter bottle or 1-gallon jug) – Apple cider vinegar (enough to fill half of each container) – 1 apple – Dechlorinated tap water – Filter floss or polyester fiber fill (stuffing for pillows and stuffed animals) – Paper towels – Rubber bands Pipette – Optional: funnel

1. The apple should be cut into small slices so it can pass through the container’s openings.

1. Divide the starter culture of vinegar eel into each container. 2. The remaining containers should be filled with 50% vinegar and half the dechlorinated tapwater. Allow air to escape from the tops of the containers.

1. You can cover the container’s openings with a piece of paper towel and secure it with a rubber band. This allows vinegar eels to breath while keeping pests out. The containers should be kept at room temperature on a shelf or in a cabinet that is not exposed to direct sunlight.

The wine bottle can be used to easily harvest vinegar eels. In case the wine bottle is damaged, the larger container can be used as a backup culture. You can leave backup cultures alone for up to a year without feeding them. While the population may be decreasing, there should still be enough vinegar eels available to start a new one if it is needed.

How can I harvest Vinegar Eels for my Fish Feeding?

1. You can leave the wine bottle alone for up to four weeks to allow the vinegar eel population to grow large enough to you can start feeding the fry. 2. When you are ready for harvesting, insert a wad if filter floss into the neck. The floss should be soaked in vinegar.

1. Gently pour a little dechlorinated tap water into the neck of the bottle.

1. Wait between 8 and 24 hours, and the vinegar-eels will pass through the filter floss to the fresh water.

1. Use a pipette to remove some of the vinegar eels and feed them to your fish fry.

Although you can feed the fish for several days straight, it is not recommended to do so for more than a week. If you have many fish babies, you should prepare multiple vinegar eel cultures. Each bottle should be rotated between the others, and each bottle should be given four to five days between feedings to allow the culture to repopulate.

How Do I Maintain the Vinegar Eel Culture?

At six months, the apple pieces start to break down and the nutrients run out. This can lead to a cloudy culture. It’s time for a new culture. You can use the old culture to fill a new container. Fill the rest of the new container with apple slices and a fresh mixture of 50% apple cider vinegar and 50% dechlorinated water. Your new culture should be ready to harvest again in two to four weeks.

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