Terrarium ventilation

Supplies needed to set up computer fan for terrarium

     When I left town for the holidays last month, I filled the bottom of my terrarium tank with water to help raise humidity while I was away.  It helped.  Some of the water evaporated, and my orchids tolerated my absense quite well.

     But some of the water remained, and I only got around to cleaning it up today.  While I procrastinated, that standing water had turned into a viscous, moldy, algal scum, which gave off a rather nauseating fruity odor.  As I was cleaning up this mess and wiping the tank with a generous serving of Physan, I decided it was time to install some proper ventilation.

     Every orchid terrarium advice article/thread I've seen strongly recommends having a ventilation system.  Most people suggest using a computer fan as a compact and energy-efficient option.  I actually ordered such a computer fan back in November, but put off setting it up until now because I was hesitant about having to splice wires. 

     Turns out, it was much simpler than I had feared.  There are dozens of articles online describing how to connect a computer fan to a USB cord.  The one I found most helpful, was this youtube video, which clearly showed everything in under 2.5 minutes.

matching red and black wires from computer fan and USB charger

     I sacrificed a USB charger from an old phone that no longer worked.  The only other tools I needed were some wire cutters, scissors, and duct tape.  I cut the fan's wire at the end of the red and black wiring, and I cut the USB cord right before it got to the end that plugs into a cellphone.  When I peeled back all the layers of insulation around the USB cord, there were 4 wires inside (black, red, white, green).  I cut back everything except the red and black wires.

red to red, black to black, and all taped closed

     At this point, all I had to do was peel back the plastic insulation around the black and red wires (this was actually the hardest part).  I curled the metal parts from the two red wires together, and taped everything closed with duct tape.  Then I did the same thing for the black wires.

computer fan ventilation for terrarium

     I've got the fan hanging from the top corner of the tank, where it can blow air diagonally across the entire length of the terrarium.  The fan is fairly weak, but I can definitely feel a breeze from a couple feet away.

Setting up a terrarium for orchids

That's his menacing face

     Frustrated with my inability to protect my orchids from my cat, I decided on a more drastic change that would permanently keep my flowers out of harm's reach.  Over Thanksgiving break, I ordered a 24 by 18 by 36-inch terrarium off Amazon.  

     

     The package arrived earlier this week.  Its width is exactly right for it to fit into the bottom area of my growth shelves, but it is just a few inches too tall.  To fix that discrepancy, I purchased 4 planks of wood (at horribly extortionate Manhattan prices) which I used to prop up the growth shelves.

Orchid grow area set-up

     Between the wood props, and the removed connector shelves, the entire setup is a little unsteady. Fortunately, the terrarium fits well into the space, and I don't expect it to get jostled very much.

     I arranged the orchids back into the terrarium.  The terrarium's 3 feet of height left enough space for even the tall spike on my Psychopsis Mendenhall. A few of the orchids didn't fit inside the enclosure, but since they're not in spike, they should be safe from the cat anyway.  Anything with growing buds is now closed off behind glass.

Spikes!

     I'll probably rearrange the orchids in the terrarium. For one, I would like to try and take better advantage of the vertical space. I am also considering adding a fan to boost the air circulation.  For now the top of the terrarium is open, which should provide some air movement. I guess I'll find out over time if it's enough.