Thanks a lot for responding to my inquiry. I believe some of the
suggested approaches might help me to solve the mold problem. There have
been some questions which I will shortly address here:
I do not know whether the white peat was sterilized before added to the
mix (I just described the composition of the commercial mix I use:
Stender B400), I autoclaved it before potting. Perlite was added
afterwards. I will go ahead now with the unautoclaved substrate,
although I remember trying it once with the same problems.
The air-conditioning I havent inspected so far, but I will.
I irrigate my plants underneath.