Hello Dorothee,
Only frozen black mosquito larvae is permitted to be sold here (because they can carry human diseases). I have no desire to attempt culturing or collecting them myself from my garden, especially since my dragonfly experience!
I have read all the posts about feeding (following your link and a link in your thread. I see that the microaaltjes are called micro worms and have been used to feed paros. Are they only suitable for feeding to fry, or do adults also eat them? The same question applies to vinegar eels.
Cheers,
Jonette