Thanks for the comments! Laurab: an experienced eye always sees more than a beginners' eye... That's why I needed your opinions.
Well, let's say that I that I am planning to try to breed them
At the moment they are in a 90liter tank together with 1 male and 4 female ancistrus and 6 cory's. I still don't know what I should do: replacing them in a tank of their own or trying to breed them in the tank together with the ancistrus. Suggestions are always welcome, as well as suggestions about food and cave sizes
As food for them I have: soaked regular and spirulina flakes, pleco tabs, spirulina tabs and frozen bloodworm, artemia and something that is called cyclops in english, I think.