I wanted to share my new ultra highland setup. I don't post much, but I got a ton of info from this forum during this build, so thank you all.
First, I somewhat suddenly found myself in possession of a few ultra highlanders via a trade, but didn't have the proper setup for them. The plants included a N. villosa and two N. edwardsianas. My highland tank tops out at about 75o F but I couldn't achieve the temperature drop needed for the ultra highlanders. It would only get down to about 68o F.
After a lot of research I decided to build a wine cooler terrarium. I pretty much followed the directions in this post by RSS: Wine Chiller Terrarium - I'm Trying It! - Thermoelectric Cooling Fun!
Here is the end product:
I started with this 16 bottle Cuisinart wine cooler that I found brand new in the box on Craigslist for $50: Amazon.com: Cuisinart CWC-1600 16 Bottle Private Reserve Wine Cellar: Appliances It has about 1'x1' of growing space. When the unit is first plugged in, it is preset to 55o F, which is close where I wanted it to be overnight.
I installed an egg crate bottom and ordered one of the solderless LED moonlight kits per RSS's post with cool white and warm white LEDs, 40o lenses and connected them to a 1.6" x 12" anodized heatsink with a fan attachment. I hooked up the lights to one of these automatic daylight timers Leviton LT112-10W 1000-Watt Advanced Digital Plug-In Timer with Grounded Plug and Receptacle and Automatic Daylight Savings Adjustment, White - Plug In Timer Switches - Amazon.com I love these things because you just enter the latitude and longitude and it automatically turns the lights on/off to correspond with the daily sunrise/sunset for that particular region. I use these for all of my setups. Tropical plants don't have dormancy requirements, and don't necessarily need daily light adjustments, but I still think it can't hurt to try to mimic their natural environments as closely as possible. I find that my neps in my tanks slow down pitcher production a bit in the winter but really start picking up again in the spring/summer.
After installing the LEDs I had three problems. 1) the humidity within the unit was too low, only topping out around 50%, 2) The temperature was only maxing out at about 72o F. When the wine cooler is turned on it is pre-set to 55o F, so I wanted it to get a bit warmer than that to get the 20o F nightly drop I was looking for, 3) the lights just didn't look bright enough.
The humidity problem was easy. I got a disposable foil poultry tin, cut it down to size, put it in the bottom of the cooler under the egg crate and filled it will RO water. When the lights turned on the humidity shot up to 90%-95%.
The heat and light problem proved more difficult. I decided to order another LED moonlight kit and heatsink and set it up alongside the first one. This certainly looked a lot brighter, but now the temperature in the unit was regularly hitting 85o F. Way too hot for the neps. If I ran the cooler during the day, it would bring the temperature inside the unit right down to 55o F despite the heat given off by the lights.
I needed a way to control the cooler so that it would maintain two different temperatures depending on if it was day or night. After much Googling, I came across this day/night temperature controller: Amazon.com : Titan Controls 702630 Zephyr 1 Day and Night Temperature Controller : Programmable Household Thermostats : Patio, Lawn & Garden which allowed me to maintain one temperature at night and another during the day. Perfect.
But... when I ordered it, I didn't read the specs closely enough and didn't realize that the unit is controlled by a photo cell that is on the unit itself, not on the temperature probe. So when it's bright the unit recognizes that it is daytime, and night when it is dark. If the photo cell was on the temperature probe, all I'd have to do is stick it in the wine cooler, and the LEDs turning on and off would help the unit regulate between night/day temperatures. I could stick the day/night controller in the wine cooler itself, but it would take up too much room within the already cramped space, and it would be awkward running power inside the wine cooler. With the water and humidity, that seemed dangerous. If I left it outside the cooler, it would only think it was daytime when I had the lights on in my basement where the setup is. Sometimes there are entire days I don't go down there, and sometimes I accidentally leave the lights on overnight. Not an ideal situation.
My solution was to run two extension cords into a closed cardboard box. One powered the day/night controller, the other I plugged into the same timer as the LEDs in the cooler and attached a couple of nightlights to the other end. I used electrical tape to cover the photo cells of the nightlights so that they would always stay on. When the lights in the cooler turned on, so did the nightlights in the cardboard box, thus telling the day/night temperature controller it was daytime. The nightlights stay pretty cool, so no worries about burning up the cardboard box.
The only other problem I had was condensation on the glass door, which I solved somewhat by placing a 40mm fan pointed directly at the door. It isn't perfect, but it helps keep the fogging at bay.
Here's a chart of the end result. You can see fluctuations in the temp and humidity as the day/night temperature controller is turning the cooler on/off to maintain temperature. The max temperature is a little higher than I want it to be, but I'll just dial back the daytime temp a bit.
And here are pictures of my plants:
Here is the N. villosa when I got it maybe two months ago
Here is the same N. villosa today
Here is one of the N. edwardsianas. You can kind of tell the pitcher in the lower right is starting to get some color
Here's my attempt at a closeup of that same pitcher. Sorry, I'm using my phone camera
Here's the other N. edwardsiana
That's it! Hopefully in a few years these plants will have outgrown this terrarium and I'll be trying to figure out how to build a much larger highland setup.