[Peter Finke]

The problem of Manticora-Knut has to be taken very serious indeed but I know of no reliable investigation. The information that Coleps spec. could act as destroyer organisms for eggs or larvae is new, at least to me. I think many friends would be grateful to you if you could tell us some more details about that genus, Knut.
If one does not know anything about such causes of misfortune with breeding, one thing is old knowledge nevertheless: the importance of the lowest density of germs possible. In aquaria, a low density is very hard to achieve. Even the best results indicate a density a hundred or thousand times higher than in natural blackwaters. The main reason why blackwater organisms seldom survive for longer in clear waters, at least are nearly unable to reproduce there, is the fact that the density of micro-organisms is in clearwater normally much higher than in blackwater.
We have only one means to influence that density in the direction of reducing it, and that’s pH. If we are lucky, our licorice will successfully propagate in tanks with a pH of 6 or 6.5, hardly more. It will work if we somehow manage to get the micro-organisms remain at a low level. But mostly we can’t. And then only a strong pH-reduction is the way out (4 or even less, German Master breeder G. Kopic once had success with parvulus only after pH-reduction to 3.0).
Knut: which was the pH when you had that bad experiences with destructive micro-organisms?