For just one red eye, a 10 gal would be sufficient, if you transform it into a high tank. I believe peace of the tropics sells www.peaceofthetropics.com sells hinges and stuff that helps you convert a 10 gallon into a high tank. On the negative side to this, it takes more work, and you may have to buy a different kind of florescent light that will sit comfortably ontop of the ten gallon while its on its side.
Mist the terrarium every day. It would be good to have a water dish with an airstone, or better yet, a small water feature or ultrasonic fogger or humidifier. A water feature is more difficult to set up in a 10 gallon inverted tank.
Set a timer for a 12-14 hour photoperiod. In the winter, you can adjust the photoperiod to 10 hours a day, and lower the humidity a little. A slight drop in temperature is good. That is one way people get them into breeding condition, if you desire so in the future.
pitcherplant7
As of now,
2 xenopus laevis
2 bombina orientalis
1 Dendrobates tinctorius
lots of carnivorous plants, fish, and birds.