How to Culture Vinegar Eels For Fish Fry

Photo of author


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? Vinegar eels might be a good choice! This live food is easy to cultivate and is great for raising babies, until they are old enough to eat baby salt shrimp.

What are Vinegar Eels?

Vinegar Eels are harmless white roundworms and nematodes. They feed on the microorganisms that are commonly found in vinegar or fermented fluids. Growing up to 50 microns in diameter and 1 to 2 mm in length, they are one of the smallest and easiest live foods to culture for baby fish. Breeders commonly feed them to newborn betta fish, killifish, rainbowfish, and other fry that require miniscule foods even smaller than baby brine shrimp (which hatch out at 450 microns in size).

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 do you start a Vinegar Eel Culture.

1. The following materials are required:

– 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 vinegar eel starter culture into each container. 2. Fill the rest of the containers with 50% vinegar and 50% dechlorinated tap water, such that the total liquid amount reaches the base of the bottle’s neck. You can leave a little air space at the top to allow for air.

1. You can cover the container’s openings with a piece of paper towel and secure it with a rubber band. This allows the vinegar eels to breathe while preventing pests from entering. Keep the containers at room temperatures in a cabinet, or on a shelf that doesn’t get 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. Backup cultures can be left alone for a year or two without any additional feedings. The population may decline a little, but you should still have enough vinegar eels to start a new culture if needed.

How can I harvest Vinegar Eels for my Fish Feeding?

1. Leave the wine bottle alone for two to four weeks so that the vinegar eel population grows large enough for you to 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 small amount of dechlorinated, tap water into the neck.

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

1. Take some of the vinegar-eels out with a pipette, and give them to your fish fry.

This method can be used to feed your fish babies for several days, or even a week. However, eventually, the culture will begin to decline. Therefore, if you have lots of fish babies, prepare several bottles of vinegar eel cultures so that you can rotate between them, giving each bottle four to five days between feedings so that the culture has time to repopulate.

How can I preserve the Vinegar Eel Culture

Around the six-month mark, the apple pieces eventually break down, the nutrients are used up, and you may notice the culture is much cloudier than usual. It’s time for a new culture. Get a new container, and pour in some of the old culture. The rest of the old culture should be poured into a new container. In two to four weeks, your new culture should be ready for harvesting again.

Subscribe to our newsletter for more articles such as this! You will receive a weekly email with the latest blog posts, videos and live streams.