The Build 3
With the core of the tree sculpted, I made a few smaller branches using flexible stainless steel gasline covered in epiweb. I attached these to the larger boughs and then got to work covering the styrofoam trunk with hygrolon.
Getting the Hygrolon to stick to the uneven surface of the tree turned out to be pretty easy. I used silicone as a glue and thin nails to pin the Hyrgolon to the styrofoam. Once the silicone cured, the nails could be removed. I used this technique to cover the styrofoam the the new branches.
The styrofoam pearl mixture has a very rough surface with many small voids and depressions. Even by itself, the material has some water retentive capacity. The Hyrolon provides both additional moisture distribution but also a much better visual surface than glaring white styrofoam - and one on which moss can be more easily established. With the tree upholstery complete, I turned to the background. I covered this in epiweb using silicone to adhere the epiweb to the walls of the vivarium.
For lighting, I debated an LED fixture - and I figure I will be getting one eventually anyway. I decided to go instead with a more aesthetic choice: I had gotten 3 150W MH lights from a retiring reefer. The lights were housed in a nice pendant fixture that I liked the look of. Moreover, I was unable to confirm that newer LED fixtures have the same height-penetration power of MH lights. With the lights sitting ~8 feet above the floor of the viv, I wanted to make sure I could grow decent moss even there.
Metal halide lights make a wonderful light (I'm using 5700K bulbs) but they are power hungry compared to LEDs and their ballasts can be noisy especially as they age. Once I satisfy myself that I can find an LED fixture for my prupose I will likely upgrade the lights (and slash my electricity bill :-)).
My next challenge was installing the misting system. My R/O system and the resevoir and pumps for the misting system live the basement below the dining room and I run their lines up through a heating vent.
My issue was needing to place and secure the nozzles in a way that didn't compromise the water-proofing of the epoxied walls. I found a solution in "expanded PVC" - a lightweight signage material. I glued 2 layers of black expanded pvc together to get a 1/2" thick strip I could silicone to the corners of the vivariam. These strips would then hold the screws used to secure the misting lines and nozzles.
I got the misting system installed none-too-soon: My deadline for construction had always been the local orchid show where I would be picking up a bevy of epiphytic orchids (plus a few other floral players like ferns and moss). I'll get to the planting of the tank in the next post.