For surface feeding babies, like Rainbows, Aphyosemions, and Epiplatys, the vinegar eel is a good first food, or a useful supplement to Artemia nauplii. It is easy to culture, but has always been difficult to separate from the acid culture medium.

The traditional method of filtering through a coffee filter is terribly slow, and usually loses all the smaller worms that would be best food for smaller babies like Bettas. Likewise letting them get into a pot scrubber doesn't get very effective separation, and the acid is almost impossible to rinse out without losing the eels.

The new (pat. pending) EEL SUCKING MACHINE^TM  (ESM) overcomes all obstacles and makes vinegar eels easier than baby brine shrimp to feed to your newly-hatched larvae. The ESM uses the natural behavior of the vinegar eels to induce them to leave the vinegar and swim, on their own, into clear, clean water.

The materials you will need are:

1)      ESM™  (500cc flask with long neck.)

2)      1 cup apple cider vinegar.

3)      1 cup dechloraminated water.

4)      1/3 cup apple juice.

5)      Filter-floss plug with extraction string.

6)      Push stick to slide floss down neck.

7)      Syringe to extract eels in water from neck.

8)      Spare bottle for extra growing solution.

For a 500cc flask, mix one cup each of treated water and apple cider vinegar.* Add 1/4 cup of apple juice as food, but not so much that the flask is filled to the neck. Remove some vinegar-water, if needed, as the eels do need oxygen and the neck of the flask is deliberately too narrow to provide enough surface area.

The final population will depend on the amount of surface area available. Any removed will be quickly replaced in a vigorously growing culture. The initial seeding with new eels may require as much as several weeks to build a full air-limited population.

A cork is provided for transportation, but it should NOT be kept tightly inserted during the growth period. The cord to the floss is deliberately made thick enough to keep the cork from easily making a seal. Just press the cork down gently, so air can pass to the solution.

The three requirements for vinegar eels are a clean acid liquid, some source of sugars, and air. The ESM is designed to provide all three in a compact form that takes very little shelf space.

If you purchased the ESM system with a starter solution in it, be advised that the solution is made a bit stronger than needed. Water will be added the first time you use it, and after that, some surplus solution is kept in a separate bottle. See the section, below on using the ESM to see the reasons.

* Distilled white vinegar might work, but often contains vermicide that kills the eels. Be sure to test on a few before risking your entire culture.

After a few weeks, a cloud can be seen below the surface of the solution in the flask. With good eyes (or a magnifier) and a bright backlight, millions of tiny worms can be seen squirming in a more-or-less vertical position just below the surface.

Pour surplus solution from a separate storage jar (or water if it's the first time) to bring the surface of the liquid to just within the neck of the flask.

Push the floss plug down to barely contact the surface.*

Add water to the neck to fill it to the top. This can be plain tap water, as the amount of chlorine/chloramine will not be sufficient to hurt the fish.

Wait a few hours (overnight is ideal) and the oxygen-starved worms will wriggle up through the floss and swim up into the clear water to get enough air.

Now you can suck worms out in clear water to feed your fish. The EEL SUCKING MACHINE really sucks! Careful pH tests have shown that the diffusion of vinegar into the area above the floss is negligible.

* The surface level can be regulated to fit the length of your dropper, as you want it to be able to just reach the surface of the floss that is about to start wicking up vinegar.

Remove the floss plug by pulling it out with the string.

Pour enough liquid out to get a sizeable surface area, again.

The excess liquid can be kept in any clean bottle, sealed with a floss plug. The eels will grow in it as well as the flask.

Squeeze liquid out of the floss and replace in the neck to block fumes from reaching the room. Lightly replace the cork, if desired.

Store both bottles away from bright light, until you can feed again. This time, you will put the surplus from the spare bottle back into the flask to get the surface up into the neck. Add a bit of water if evaporation calls for it.

The initial solution will work for months. If production drops, add a little apple juice. If it gets too cloudy and full of mulm, make up a new batch in a quart jar, seeded with some clean worms, and replace the dirty one with the clean new one as soon as the population appears to be growing OK.