NO terrarium. The mix can be a 50/50 mix of peat and perlite or peat and sand. Distilled or rainwater only, unless you have or install an RO filter. I use rainwater. Place the plant in a bright window. Sit it in a tray of the water about 1/2 deep.

I have heard many other people that have said yes to the terrarium.

Well, good luck with that.

I don't suggest a terrarium for an adult plant but it's easier to germinate seeds in one. Distilled,RO or rain water only. I would go with 1/1 Sphagnum peat moss/sand for Drosera. You need to use silica sand or from what I've heard Play sand. Silica sand can be found at swimming pool stores.