Small terrarium for jewel orchids question

[mrt]

Hi all,
I got a couple of jewel orchids:
* macodes petola
* ludisia discolor var. alba
* anoeoctochilus formosanus
as the days are becoming shorter here, and the days become darker, I was a bit afraid that the orchids may have not enough light (unfortunately, my appartment has only north facing windows, so it is already quite dark).
While I was thinking about making a little growlight (I am an electronics engineer and work with optoelectronics, so I do have loads of different LEDs here, which do have a daylight spectrum which should be fine for the plants) I was searching the net and also came across this board. Some people seem to have their most valuable and sensitive plants in a terrarium.
I do have a 30 x 30 x 30 cm glass containter (was an aquarium before, I guess) and I thought I would make a setup as follows.

I would construct a lid for the glass container which holds the LEDs and also works as heat sink. I could also add a humidity sensor.

Then my idea was to put the orchids, with their pots, into this glass container, close the entire thing with the lid and use the LEDs mounted on the lid as growlights. Add a timer which switches the light on for 12h.

I am unsure about a couple things, though.

a) if this is kept closed, I assume it would grow mold quite quickly, would it? so I would add a little ventilator and humidity sensor and as soon as the humidity is above, say, 80%, the ventilator is switched on. Bad idea?
b) is 30cm maybe too shallow for these little orchids? mine does not flower yet but I saw pictures and I am not sure how tall the flower stalk will be.
c) instead having the container completely closed with the lid, is it maybe better if the lid is partially open and covers maybe only half of the opening?
d) maintenance: I always wonder how people having such a "terrarium" conduct the maintenance. For example watering. I don't want to add a mister, so I guess I would have to remove the pots regularly, water them and put them back into the container. Seems like it is quite a bit of work? however I am unsure how long this thing will stay moist enough for the orchids to be happy. Any experiences? is it perhaps a bad idea to have the orchids within their pots inside this container?

[wisdomseeker]

Excellent questions. You are definitely doing your homework, which usually results in success. Sounds like you are on the right path with your set-up.

30cm should be fine, initially. Ludisia discolor can get a bit hefty on size compared to Macodes & Anoeoctochilus. Quick question. Can you explain a little bit more about the "ventilator" you mentioned?

This is just coming from my end (an opinion): I believe any terrarium set-up will need to be tweaked somewhat (trial & error) to find that 'desired sweet spot' for happy plants.

I've grown several species (and hybrids) of jewels successfully inside terrariums of different sizes, including 12" (30cm) cubes. My terrariums are mainly utilitarian, used for mounted and potted orchids. The 12" cubes I've been using have glass tops. They are passively vented (a small 3/4" gap on the top... so the glass top does not fully cover the entire terrarium. Other set-ups are almost completely closed (small gaps around the doors of these terrariums), so I use forced air inside the set-up for circulation (small computer fans).

My jewels are grown potted using net pots. I use small bark as a growing substrate. I also have shallow pans/saucers (about 1.5 - 2 inches deep) with live sphagnum moss growing inside of them (filled with anywhere from 1 to 1.75 inches of water). My potted net pots are placed within the pans/saucers nestled around the live sphagnum. By doing this (from lots of observation, along with trial & error) I can maintain a RH level of around 70-80% within my set-ups.

The bark substrate is kept moist all the time (water from live sphagnum pans/saucers wick through the net pots and keep the bark substrate at the desired moisture levels that "my jewels" seem to like. I top off the live sphagnum pans/saucers with distilled H2O on a consistent schedule (most of the water evaporates in about a week's time).

Pots can be easily removed from my set-ups for flushing/fertilizing/watering when needed (very low maintenance and does not consume much time). I've been successful with medium low artificial LED lighting (photo-period of about 10 hours), RH around 70-80%, temperatures average around 76-82F year round during the day, and knocking down to about 10 degrees F lower at night (depending on the time of year, eg. winter time). My jewels thrive and are happy with this routine.

A couple photos to give you an idea of how they are potted (might give you a better idea of what works for me). Keep us posted on the progression of your terrarium when you get a chance.



Late post tack-on: Set this little 8" x 8" x 12"high (approx. 20x20x30cm) terrarium up last fall. Made some orchid divisions (from my main terrariums) that I wanted to keep, but really did not have any space to keep them. So I used this small enclosed glass container to house the extras... an 'overflow' container of sorts. Just a no-cost temporary solution for my extras (already had it sitting around collecting dust). Still have one bulbophyllum in there as of today, and it has done well.

More or less it's completely closed (except for a narrow gap on top). Photos below. Adjusted light intensity by using a small piece of black plastic needlepoint material on top. RH stays around 70-80%. No issues with mold or fungus. Bought some inexpensive (but good quality) digital hygrometers/thermometers some time ago that are used for chicken-egg incubators and made in the USA. Used one of those inside this set-up and have been surprised with it's accuracy, also pleased with duration.

[estación seca]

Welcome to the Orchid Board!

[mrt]

Hi guys,
thank you for your messages!

I made a little progress with my terrarium.
I built the LED lights. For these I used LEDs which are supposed to have a "neutral white" spectrum, with two peaks at 450 nm and around 600 nm. Color temperature is supposed to be 4000 K.
I have milled a piece of aluminium and glued the LEDs with heat conductive glue on it. There are 4 LEDs, each of which has 400 lumen. In total this results in 1600 lumen. With my 30 x 30 cm surface area, this should give around 16000 lux, which I believe is good for the orchids. I found no reliable numbers for this, though. I do have enough headroom such that I could make the light even brighter, and of course if it is too bright it can easily be dimmed a bit.

The reason I use 4 LEDs is that with only one LED, the light would not be distributed so evenly. I placed the LEDs such that the area they illuminate is as homogenously illuminated as possible.

Does this all make sense?
will post photos of my LED light when it is completely finished.

I am still wondering whether my glass box does need a little fan to produce some airflow. I am afraid of mold, but on the other hand, when the air is exchanged too much during winter time, the humidity will drop a lot I assume.

[wisdomseeker]

Originally Posted by mrt

Does this all make sense?

Makes a lot of sense. Sounds like a well thought out light build. I have always liked the option (having ways) to brighten or dim a light fixture. Good you were able to distribute the light evenly. Being that LEDs are a point source of light, sometimes light spread is overlooked in a build.

You can always experiment with a fan. Maybe put it on a timer and have it energize at certain times (especially if you can monitor your humidity levels and then adjust as needed). A possible downside with fans is that they take up a little bit of the terrarium's real estate. Some fans can also be a 'bit' noisy to one's ears.

[tmoney]

hey there....im a total beginner so take anything i say as such. but i can provide a beginners experience/perspective in regards to the tank. so my little terrarium, basically the same size as yours (just remeasured and mine is 31x31x35 cm, exoterra with the doors), and here are a couple things ive learned:

first is that air movement is important and for many of the species (can’t speak to those jewels specifically, tho) it is necessary. i didn’t have fans at first and quickly got mold. then i got 2 reptile fans, one hanging about midway down on one wall, the other mounted with bonsai wire to the screen lid and blowing down. this was a bit too much air movement i think, and after about 2 months the hanging one had corroded and stopped working. i never replaced it and the tanks been with just the one fan and the plants seem happier. and no mold for months.

im all about convection, so i feel the placement of this one fan is really helping to distribute heat and humidity. it should also be noted that i have basically closed the tank (except for the small holes and gaps everywhere, common to these types of tanks), so the fan is just helping to push the air around. fresh air is brought in daily when i open the doors to spray.

as for watering, because i want the tank to be as cheap and easy as possible, i now just spray by hand. daily good spraying for a couple ghost orchids and mounted ones. on saturday watering days, i drench all the orchids in the tank, including the ones that are tucked in little niches with some moss and leca mix in their root pockets. dilute fertilizer spray. then in the evening on fertilizer days i drench the whole tank again as a flush. let the water sit overnight, then the next morning i manually remove the standing water with a big plastic lab syringe and a drinking glass.
im sort of in a different direction than you since you seem to be wanting to keep them in pots mainly, or mounts. i would think this should make everything even easier for your care and culture.

buuut, this is my ghetto orchid tank approach, but the plants that are in there seem pretty happy. i have a “throw poo at the wall and see what sticks” attitude toward my terrarium. however, you are light years ahead of me on your lighting ( ) so, im following your light set up to learn more....thanks for your detailed light info, please keep putting up more!