Questions: Small Orchidarium

[SvenLittkowski]

Hi,

I got three very small rainforest orchids (I live close to the rainforest in Jamaica), and want to build for them a small orchidarium. I will need your assistance with expertise.

I thought to use mirrored glass (the mirror layer inside the box in order to reflect the fluorescent light a bit back to the plants). The width is not more than 30 cm, the depth is 20 cm, and the height is also 20 or 30 cm.

All sides are glass.

At the back, I want to have a lime stone in which are wide cuts. In those three cut-outs I want to rest tree branches (with bark), on which the orchids are mounted.

I also was thinking to have a little water pond at the bottom with a mistmaker inside or a water pump. In case of a small water pump, on top of the lime stone is another small water pond with a mist maker inside. The mist will bring moisture into the air.

The one or another way (mist at bottom or top), I also want to have a small 12V fan inside and a small cooling plate, to make the air a bit cooler than outside (since the rainforest is coll as it spans between the peaks of the Blue Mountains).

At the top will be a fluorescent light.

What do you all think about this setting, based on your expertise?

[WhiteRabbit]

[SvenLittkowski]

There is no text in that posting...

[WhiteRabbit]

Originally Posted by SvenLittkowski

There is no text in that posting...

sorry - I used a smiley to bump your post

[SvenLittkowski]

Ah, thanks. :-)

Meanwhile, I came upon two more questions:

1.
I am using one light source, a flat energy-saving fluorescent light bulb on top of the box. To reflect the light best from the ceiling above the light bulb, should the ceiling be a mirror, or aluminum foil? What's better in reflecting light back downwards?

2.
There will be a glass plate between light bulb and main box, to avoid heat emission from the light bulb. Should that separating glass plate be fully transparent (normal) glass, or milky glass, or roughened glass?

Thanks.

[Discus]

Sven - I've not got significant experience of growing in terraria (none) but have read on the subject and have various plants under various lights (T5 HO of various types).

with regards to your questions in your most recent post, I'd say mirrors are better light reflectors, but aluminium can be more easily shaped. If you were using aquarium style tubes, you could use aquarium reflectors, but I see you're not.

I would make that glass clear (because "milky" glass will not only diffuse but also absorb light). I don't think you need to worry too much about diffusing light; if it's too bright you can move the plant or the bulb, but not enough light is usually a problem rather than too much (although I have no idea how much light your native orchids need).

---------- Post added at 11:49 AM ---------- Previous post was at 11:46 AM ----------

re: temperatures, I'd suggest comparing what your terrarium does vs. the typical temperatures at the altitude your plants come from once it's built; I imagine your growing area is airconditioned and this may be cool enough without the peltier block (which is quite a hard way of cooling any significantly large volume without a lot of engineering and usually several large peltier units, possibly stacked, depending on the temperature differential you wish to maintain).

[SvenLittkowski]

Yes, but simple. I was thinking of the combination of a small fan and only one or two of those:
ebay.com/itm/300882134919?ssPageName=STRK:MEWAX:IT&_trksid=p398 4.m1438.l2649

[Discus]

That ebay link failed.

There have been several discussions on these forums about the ineffectiveness of peltiers (this may stem from over-enthusiastic expectations as much as anything) and there are lots on other terrarium fora about how peltiers fail. Expecting a more than 5-10 degree differential out of peltiers seems to be wishful thinking. (i.e. expecting your tank to be more than 5-10 degrees cooler than your room). This assumes that the "hot" side of your peltier is at or close to ambient room temperature; if it's not, you're going to be fighting a losing battle - you'll need a good heatsink and fan, and for the peltier to be able to transfer heat easily into the heatsink for this to stand a chance of working.

Many suggest using an aquarium chiller to achieve effective cooling [use the chiller to cool down a waterfall or similar] (or even modifying a wine cooler to serve as a terrarium).

If you want it, here's a reasonable write up of someone using peltiers for highland nepenthes:
CPs Terrarium: Cooled Terrarium Note how massive his heatsink is


---------- Post added at 05:52 PM ---------- Previous post was at 05:47 PM ----------

Another page I read recently also made the point that if you're looking to shift lots of heat, you want to use peltiers in parallel (next to each other); if you want to cool a lot you use them in series (stacked) - and if you want both, well, I guess series/parallel it is!