I'm new at this, so consider my reply in that light.

I prefer glass because it's typically more clear, thus it just looks better to
me. If you use a metal can and lid, no sunlight would reach your system.
Wouldn't it die in a hurry with no sunlight?

Soil and land plants would be great. Back in the 70s folks used to do just
this. Read up on "terrarium". I think you'll want a good seal because the
water that evaporates from the dirt and expirates from the plants is the only
water that your plants will get. It needs to condense on the inner walls of the
container and run back down into the dirt. If it escapes, then your plants will
not have enough water.

I seem to remember in the 70s using a layer of crushed charcoal (as in that used
for aquarium filters) as a bottom layer, under the dirt. I don't recall why,
though.

Good luck.

Steve


--- In homemadebiospheres@yahoogroups.com, tejjammy <no_reply@...> wrote:
>
> This is my first post and i have a few doubts which i believe you all could
clear.
> They are :
>
> > Instead of using glass bottles or spheres, can i use a large PET bottle or a
can?
>
> > Instead of a common theme of an aquatic ecosystem, can i have an ecosystem
in which i ass soil and some land plants?
>
> > How long should i wait before sealing the ecosystem?
>
> Waiting for replies........
>