alright, i consider myself fairly experienced with satanics, and honestly if you're looking for the "best" enclosure for him, you're gonna want to go with something larger. dense foliage is a good thing, but space is as well. while i would normally say that a screen top isnt a bad thing, that enclosure looks so small that surface area:volume ratios dictate a lot more of your humidity is gonna get out. covering half of the screen isnt necessarily a good idea either, because you need adequate ventilation to minimize mold growth and such, which is a common problem in keeping a cool, yet highly humid enclosure. people are kinda misled about the necessity of maintaining high humidity for these lil guys. twice daily (once during the day, once after lights go out) thorough sprays of the enclosure should be sufficient to keep the humidity up through the day, and give them water to lap up off the foliage at night. allowing the cage to dry out during part of the day helps minimize the growth of mold and baceria.
if all you have is a single individual, try moving him up to a 10 gal, at least. i used to keep pairs in 15 gal talls. the thing with what you've got going on now is that yea, it does have plenty of cover, but that seems to be all that he's got going for him. satanics can get a lot more active that people normally realize at night. you should supply just about as much cover as space for them to jump around and whatnot. during the day, they'll sleep in the cover, and at night they'll come out and hang around on the twigs and branches, if you supply them. for anything arboreal, the taller the enclosure the more i think they would benefit from it. i just think people get the wrong idea that just cuz you have a smaller gecko means that it needs a smaller cage. personally, i only use the plastic critter keepers for transport and while im growing up hatchlings. with the foliage so densely packed, when you spray, all of the water is gonna be channeled to certain leaves and off to the sides before it reaches the bottom. just think of the last time you stood beneath a tree when it rained.
finally, i would recommend switching to live plants. i've done it that way since the beginning, and it can really help you out because if your plants begin to wilt, its a good sign you arent putting enough water in. the live plants will also, in my opinion, hold the water more as the silk plants may tend to absorb some. keeping the substrate moist not only helps the plants out, but it provides a time-release for the humidity as the substrate dries. thats part of the reason why natural enclosures tend to hold their humidity better than fake plants.
let me see if i can get some images to work here...
an old 15 gal tall i used to keep a pair in. it's got enough to shelter them in the plants, and theres plenty of space to hop about on top.
now this is the big, long tank i keep a large group of 3.3 in, where a lot of my success has been coming from. ficus is a great plant for these guys as it can be dense, and basically the leaves look exactly like their tails. the vines are actually old dried honeysuckle vines, and they often perch themselves on these once the come out at night. pothos is nice, but can easily overcome an enclosure, so you might need to trim it back time to time. leaf litter is also a good idea, especially for females to lay eggs beneath. i know you're only working with a single male, but its something you can decide whether or not to use. oak leaves work well as they wont mold, i would recommend picking live leaves from an oak, then drying them yourself so asto minimize the chances of bringing in unwanted mites and whatnot. anyhow, heres the other pic.
hope it helps.
