[helene schoubye]

Yes, I understand that, – I think I mentioned this problem to you 😉
For myself the best way it works is to have nice little tanks with pairs but not breed intensive, this way I manage to keep enough fish from one species to keep going, but only sometimes to have problems with too many of one species.
My p. nagyi ‘cherating’ though is kind of an exception to this, – they get so many off springs. Just today I rearranged a small 12 liter with one pair, – I took out 6 about 1,5 cm big fry, but there were so many small ones still in there. There are probably still 10 small fry in the tank. I have had that before with this species, – sometimes there’s a pair that just produce so many offsprings even in these small tanks and with no interference from me.
So thats an easy species to be grandfathering 🙂
I wish the parvulus would be the same, but no, they get only one or two offspring. They could do with some intensive breeding, but I have never done that.