Vinegar eels (Tubatrix aceti) are perhaps the most hands-off of any live food to culture for an aquarium. Once set up, they can go many months, even up to a year, without maintenance. Though it is recommended you keep tabs on them more frequently than that to keep optimal production. Vinegar eels are best used as a fry food, and though they are a nematode, unlike microworms they swim to the top of the water column rather than sink. This makes them invaluable for tiny, surface feeding fry such as anabantoids and killifish. They can also make a nice treat for adult nano fish (<1” in size). What you will receive is a 5 oz culture that will be well started.

How to use: To culture, all you need is a starter culture, apple cider vinegar, treated tap water or RO water, a long neck bottle (such as a wine bottle), filter floss, paper towel, a rubber band, and apples. The bottle should be filled up to before the neck with half freshwater and half apple cider vinegar. Then slice up part of an apple to fit into the bottle. Add the vinegar eel starter and pack some filter floss in the neck of the bottle. Then simply cover with a piece of paper towel wrapped in place with a rubber band. The culture takes about a month to really get going. Once you see a good production of vinegar eels in the bottle, you can harvest by adding freshwater above the filter floss and waiting a few minutes for the eels to swim up. After a decent amount has collected in the freshwater, you can pipette them into your aquarium. Alternatively, you can pour some of the culture into a coffee filter and then dunk the filter into buffered and treated tap water (buffer to combat the acidic vinegar) before feeding to your aquarium.

How to Store/Maintain: Cultures should be split every 2-3 months and fresh apple should be added periodically to keep them productive. Keep the cultures in a cool, dark place for best results. You will receive your culture in a 5 oz bottle. It is recommended that you use some of this to start a larger culture, however what you receive can be harvested in a pinch.