Pots suitable for semi-hydro?

[karrolhk]

What do the pots for semi-hydro look like?

1. Should there be an inner pot with holes for water to escape in flushing, and an outer pot without holes to catch the water and with a reservoir?

2. Or, can it be just 1 pot without holes (e.g. a vase)? If so, how to remove/exchange/clean out the water in the reservoir from time to time?

Any explanation with pics would be fantastic.

Thank you.