Thank you, Piotr
She seems to be relaxed and in control at that time. But in the end - she did get problems keeping all of the other fishes away (to much stress).
Also she didn't allow the male to come close to the nest at this stage, so he was not able to help her in the "frontline".
I moved out all the other fishes at one point. Then they spawned one more time, and for the first time i could witness xinguensis eggs hatching in the main tank. Then, after they had hatched, she began to let the male come closer and closer to the pit (but still not
too close).
Unfortunately all of the fry was gone after three-four days, for some reason. Then they never spawned again... and now they are dead
The 12 individuals i now have left (the offspring) will be taken extremely good care of, no doubt about that. Can`t afford to loose these guys, since xinguensis seem to be nearly impossible to get a hold of these days!