I have used vinegar eels before, harvesting them in the way Peter describes, – its not so difficult actually.
I use this bottle
Its an old dressing bottle 🙂
I use some old filter material to put in – not cotton-wool, you have to make sure its not too dense so that the eels cannot move through it. But still dense though, as you wish to keep the vinegar seperate from the water. I suppose (I have not yet tried that) but in fact you might be able to use soft water so as not to introduce hard water to any tank you feed. Why the water keeps seperate from the vineager I dont understand, but it seems so. I have sometimes tested the taste, because I worried (what you dont do for the fishes :woohoo: ) but it does not taste of vineager.
If you have a good culture of eels, they sure will crawl up in thousands …
You dont actually have to have more than maybe 3-4 cm of water, its easyer to draw them up with a pipette if theres less water. And you can refill with water.
The paramecium I feed directly, – those I feed with coffee cream, a drop a day for a glas