I think the best is to have two ventilation slits over the full length of the
growing chamber, one (almost) at the bottom-front, and one at the top-back.
In this way you will get a passive ventilation through convection caused by
the
heat produced by the fluorescent lights (this works only if the lights are
-inside- the chamber). When you want to regulate the ventilation, you can
simply cover the top slit more or less.
My experience with a closed growing chamber was that the plants were doing
well, but the fungi too!
>
>4) Orchid growers: Has anybody successfully grown highland
> nepenthes and masdevallias together? Seems they should do
> well together (masdevallias grow in the Andes).
At the botanical gardens of the University of Amsterdam (VU), they have a
Nepenthes collection together with a Masdevallia collection (at least, they
had a few years ago). The plants (both Nepenthes and Masdevallia) were doing
very well, unfortunately I don't remember which species (or hybrids) they had.
Martin Zevenbergen
Martin.Zevenbergen@algem.pt.wau.nl