> I just aquired a 55 gal. (220 L) aquarium tank and I am wondering if it
> should be entirely closed up or if there should be a flow of fresh air into
> the tank.  The Nepenthes I will be growing in it are plants such as NN
> bicalcarata, truncata, rafflesiana and other lowland plants.  Right now I
> have it entirely enclosed and am worried about stagnant air.  
       I have a fair-sized hybrid (N. X mastersiana?) and a small (still 
       unrooted,) alata in a sealed case which I open maybe once a week 
       and give a good misting.  I also empty out built up water monthly
       or so.  They're thriving beyond my wildest expectations (I never
       had much luck with Neps before,) so I'd say go for it...
       Hope this helps.
               Happy growing,
                       Peter