Thank you all, its really interesting, – 🙂
I could now set up 3 tanks trying out
1. stable temperature (sounds quite interesting, Ted)
2. really careful, intensive feeding of fry from very early
3. a tank with more fokus on humic acidity
Its not much of a scientific experiment, but I will try tbem out, – anything that will change. I dont know what to keep doing with these ‘single’ male harveyis, I already have a 60 liter full of them 🙂
So something must be done.
But again, – it still puzzles me why only the harveyis and why all broods, not just once, but more times.