How do you drop temps in a terrarium?

[nzadro]

Hi all,
I was wondering how you deal with getting night time temp drops for your orchidariums.
I just purchased a mounted nbs trichocentrum tigrinum from Hausermann. I knew it would do fine in my small exoterra terrarium, which has temp in upper 70s low 80s, and humidity around 75 to 85%. I was told it'd do great & it wasnt expensive so I bit the bullet.
Upon further reading on Travaldo, I see that it suggests a drop in temperature at night.
I am kind if at a loss here, opening the terrarium does nothing expect lower the humidity. Any suggestions? Stupid question but...does it matter? New to growing enclosed orchids. Thanks in advance. Natalie

[estación seca]

First, I've never grown that plant. If somebody has, I hope they speak up.

Most people don't drop the temperatures in the terrarium unless they live somewhere they can open windows at night and it's cool. We read about plants wanting a drop in temperature at night, but a lot of them seem to do pretty well without it. If the daytime temperatures are a lot warmer than the plant wants, they will definitely do better with much lower night temperatures. But most people don't worry about it.

Carnivorous plant growers and really wild fish keepers do all sorts of things like pumping cold water from a cooler filled with ice and water through their cool plant terrarium or aquarium. Some people put a heap of ice on the top of the terrarium. I have even seen a report of people sticking tiny heat exchange electrodes on the glass

[Ray]

Peltier Coolers

[hypostatic]

Originally Posted by Ray

Peltier Coolers

You could also macgyver a computer water cooler to the tank to cool it.

Here's the peltier/TEC idea implemented:
How to build a Heliamphora Terrarium (And How to Install a Peltier Cooler) - YouTube

It looks like the "peltier system" they bought for the video was something like this:
Thermoelectric Peltier Refrigeration Cooling System Kit Cooler Fan DIY 12V 72W | eBay

[RoryOMoore]

Hi Natalie,

I live just across the river from you and have the same climate. I don't grow the orchid in question, but I do grow orchids in the Pleurothallis Alliance. My house doesn't have central cooling so I rely on a window unit for the room my terrariums are in. I keep the day temps at 75F and at between 9-10pm I drop the temp to 62F. One day I will pony up for a window unit that has a day/night temp setting option and just set it and forget it. So far that has been my solution. Hope it helps.

[estación seca]

If you read the fine print in those articles the Peltier devices in real-world use provide minimal cooling, unless perhaps the entire glass surface were occupied with them. Think about it: Even if you could keep solid carbon dioxide ice always attached to a small area of the terrarium, the heat gain from the rest of the surface would overwhelm the chilling.

The two most widely-used solutions are 1 modifying a refrigerator of any size with electric lights; 2 using a pump to recirculate chilled water between an ice chest and pipes underlying the terrarium substrate. That means drilling the ice chest, installing the piping, drilling the terrarium, installing the piping, setting up the pump, filling the ice chest with fresh ice and water each day and cleaning the chest and pipes regularly. Wouldn't it be a lot simpler to fall in love with one of the 2,000 orchids you could grow without a chiller?

[nzadro]

First off, thank you for the responses! I appreciate it so much.

Most people don't drop the temperatures in the terrarium unless they live somewhere they can open windows at night and it's cool. We read about plants wanting a drop in temperature at night, but a lot of them seem to do pretty well without it. If the daytime temperatures are a lot warmer than the plant wants, they will definitely do better with much lower night temperatures. But most people don't worry about it.

Thanks, estacion! This makes me more at ease. My tank mainly houses small begonias, so the change in temp is not always ideal for this genus. Have you ever had trouble inducing blooms without the "necessary" temperature drops?

Peltier Coolers

You could also macgyver a computer water cooler to the tank to cool it.

Whoa nelly. That looks hella interesting! And also hella advanced, haha. But I have never heard of this, thanks for bringing it to my attention and attaching the videos. My current tank is 12x12x18, so not on the large size. I wonder how that would work.

Rory, neighbor! Thanks for the input. My main concern is that it is summer and opening a window is out of the question, ha ha! My window unit AC is in my bedroom & not close to the terrarium. Tiny NYC apartment.
Do you keep the terrarium close to the unit? I am surprised it'd cool down so much.
I got a small computer fan, hopefully that can help circulate and cool the air slightly. I worry too much may affect my begonias negatively.

[clintonsparsons]

If I knew how awesome making a chamber out of a fridge is, i would have done it a decade ago.

[DirtyCoconuts]

What about a cool mist system? You can set it next to the terrarium and add a timer so it only mists for say 15 minutes at just after sundown.... that would take the heat out of the box and perhaps drop the temp a bit until next morning.

[estación seca]

Originally Posted by clintonsparsons

If I knew how awesome making a chamber out of a fridge is, i would have done it a decade ago.

After that teaser, you must tell us more.