# Jewel Orchid & Begonia Bowl Terrarium



## Harpspiel (Jan 18, 2015)

I just bought an 8 gallon glass bubble bowl to make an open-topped jewel orchid/begonia terrarium. It's 12" tall x 16" wide with a 10" opening on top, to give a sense for size. My ambient humidity is around 20-30%, and I'm hoping that once the plants grow in they'll create enough of a humid micro-climate in the glass that I can leave the top open, but I will be covering it at least at first, airing it out a little each day and watering as necessary. The idea here is to go as low-tech as possible.

Given my low humidity, I don't think that wicking from the drainage layer is necessarily a bad thing. I'm intending to do drainage layer, then screen, then ABG. I'll add in substrate from my tank so I should be able to get a springtail population started. Would lava rock gravel work as well as LECA as a bioactive drainage layer? The LECA product I'm looking at is Josh's Frogs false bottom, it looks like it's a nicer dark brown than other products, but I think black lava rock would look really nice. Or should I go with something that wicks less, like Matala?


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## Harpspiel (Jan 18, 2015)

Oh suggestions for ABG materials are also welcome, I'm going to try making my own. Horticultural charcoal - "coarse" or "fine"? Orchiata orchid bark - "classic" or "precision"?

And intended inhabitants, for those interested:
_Anoectochilus roxburghii_ (dark leaves with copper veins)
_Anoectochilus roxburghii _(emerald green leaves with single silvery midrib)
_Begonia baik
Begonia metachroa
Dossinia marmorata_ var. Dayii
_Macodes petola
Marcgravia sp. _Azreal - maybe
_Selaginella picta_

Hoping to get a _Malaxis metallica_ and _Begonia_ sp. Julau in future, I'll see how well this set fills it in.


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## jgragg (Nov 23, 2009)

I think since it's all hand-watering you ought to be in great control of how much excess water you apply (or don't). Therefore I don't think you need to assume there will be free water in the drainage layer available for wicking. I mean, put it there if you discover you need it, to maintain high enough soil moisture for leaf turgor, but otherwise - just _don't_.

So with that in mind I would suggest using whatever looks best. I like the black scoria idea the best, personally.

You could also approach the question empirically. How much does scoria wick, anyway? In the event you did want to maintain some free water down there, say for vacation freedom or whatever - how far will it wick upward simply due to capillary action? Someone on here (Chlorophile???) did some empirical work with clear glass jars and various media.

Anyway - sounds like a sweet little project! Have fun with it.


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## Chris S (Apr 12, 2016)

You just need to decide the order of importance:

Look and feel?
Organic(ish)?
Wicking potential?

Matala doesn't wick. That's probably the only plus. I actually love it, because I find my older terrariums with LECA wick moisture way too much. The other two are more of a "what looks better to you" decision.


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## Harpspiel (Jan 18, 2015)

jgragg said:


> I think since it's all hand-watering you ought to be in great control of how much excess water you apply (or don't). Therefore I don't think you need to assume there will be free water in the drainage layer available for wicking. I mean, put it there if you discover you need it, to maintain high enough soil moisture for leaf turgor, but otherwise - just _don't_.
> 
> So with that in mind I would suggest using whatever looks best. I like the black scoria idea the best, personally.
> 
> ...


Good points! I like that vacation freedom idea. In this case it sounds like wicking will be a benefit, since I can control how much standing water exists in the drainage layer.


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## Chlorophile (Jun 29, 2017)

jgragg said:


> Someone on here (Chlorophile???) did some empirical work with clear glass jars and various media.


Wasn't me, though it's a good idea. I know what you're talking about...will try to find it.

Edited to add: this thread by minorhero, maybe?


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## jgragg (Nov 23, 2009)

That's the one! Yep, thanks for digging. People could benefit from revisiting that not-so-old thread.


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## Harpspiel (Jan 18, 2015)

jgragg said:


> That's the one! Yep, thanks for digging. People could benefit from revisiting that not-so-old thread.


This is making me rethink the drainage layer in my paludarium - I started with PVC rounds and egg crate, but added perlite because so many springtails were falling through. Now I'm thinking the perlite is contributing to the constant "almost wet" condition of my substrate. Still don't know what to do about the springtails though.

But I'm going with black lava rock for the jewel orchid terrarium, and will control standing water in the drainage area depending on the moisture level I'm looking for.


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## fishingguy12345 (Apr 7, 2019)

Harpspiel said:


> This is making me rethink the drainage layer in my paludarium - I started with PVC rounds and egg crate, but added perlite because so many springtails were falling through. Now I'm thinking the perlite is contributing to the constant "almost wet" condition of my substrate. Still don't know what to do about the springtails though.
> 
> But I'm going with black lava rock for the jewel orchid terrarium, and will control standing water in the drainage area depending on the moisture level I'm looking for.


The springtails can and will climb back up if they want to


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## Harpspiel (Jan 18, 2015)

fishingguy12345 said:


> The springtails can and will climb back up if they want to


Out of the 1” of standing water and up the PVC? At first I was seeing hundreds floating down there...


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## fishingguy12345 (Apr 7, 2019)

Harpspiel said:


> Out of the 1” of standing water and up the PVC? At first I was seeing hundreds floating down there...


Yes! The climb glass lol


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## Harpspiel (Jan 18, 2015)

fishingguy12345 said:


> Yes! The climb glass lol


I have never seen mine on glass, but I'll take your word for it.


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## Harpspiel (Jan 18, 2015)

Here it is, I’ll need to wait on seedlings to grow in my paludarium before I can take cuttings for this tank, so right now it’s just _Begonia metachroa_, _Begonia baik_ and _Anoectochilus roxburghii_:

















I went with black lava rock and its pretty much invisible, happy about that. The thermo-hygrometer is temporary to get a feel for humidity in the bubble vs. in the house, I’m pretty happy with that 54% because my house is probably 25% right now. I think I’m going to cover it at night to until the plants grow in, then take off the cover and mist the ABG in the morning.


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## Harpspiel (Jan 18, 2015)

The bowl terrarium is growing in well - I figured it would take about a year to become what I had envisioned, and I would say I’m on track for that. The smaller jewels have an odd, meandering growth habit so I’ve moved them around a bit.










































I ended up drilling some holes in the cheap plastic lid, and it seems to allow just the right amount of air exchange - I don’t have any mold after two months, I get a little condensation in the morning when the sun is brightest but it dries up in a few hours, and I water a little bit once a week.


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