my total knowledge used to make this terrarium is based on the first link. ICPS..barry rice's faq on VFT. it is really amazing and taught me a lot about these plants.
is this what u mean about covering up the perlite and adding a pipe + a plastic container to get water But since water will be in perlite layer...I don't see the purpose exactly. The pipe should be in perlite for anything.. IMO.