Question
Hallo.
I would like to ask you if the pitchers of Nepenthes and Sarracenia should be full with water, half full or empty.

Answer
Hello Sed,

It is according to whether you are talking about Sarracenias or Nepenthes and what particular species of each you are inquiring about as to whether there should be any water in their pitchers or not.

The basic rule I go by is if a pitcher plant of any species or genus has a lid over the top of the pitcher opening, it allows very little, if any, rain water in, so the plant produces its own fluid whenever it feels the need to. If there is no lid, or a very small lid over the opening of the pitcher, the plant likely allows water to drip into the pitcher when it rains and can be filled about half-full of water every so often.

The main thing is not to overthink these plants. Just do what seems natural to them and they will do just fine.

Christopher