I live in San Francisco, which has a cool, somewhat humid climate. I keep my ampularia in a little glass terrarium, and I have it water itself with a timer. It waters itself for 2 minutes a day. I have the plant sitting on top of an upside down pot, which is in a small reservoir of water. The picture makes it look like the nep is IN the water, but it's not. Here's the simple setup:
The temperature goes up to about 85 during the hotest part of the day, when the 400watt MH light is augmented by the late afternoon sun. At night, the temp drops to the mid to lower sixties. The humidity is always over 75%. So far, it seems to like the conditions very well, and just produced this big pitcher, which is about three inches, not including lid:
Incidentally, it is potted in pure lfs.