@ Rick:
Thanks fot the compliment. And about your questions, the enclosures for the (almost) adult garters are 115x50x50 cm, and the enclosures for the babies are 75x35x35 cm.
We use in all the terrariums spots of 25 watt and we never had any burnproblems at all

We also have a dimmer (??) on all the lights, so we can slowly turn down the lights. And if it's hot outside it's handy to drop the lights and with this the temperature.
Under the spot 30-35° C and elsewere in the enclosure 20-25° C. The garters can choose by them selves where they wanna be.
In the upper enclosures it's a bit warmer.
I hope you understand my bad english
