Terrarium conditions - avoiding mold

[OrchKid]

Hi, folks!

I'm on my never-ending quest to figure out what the heck my orchids are trying to tell me, and keep a leash on exponentially increasing their numbers in the course of a month.

So - the setup:
I have an Exoterra, 12 x 12 x 18. There are about ten orchids in it. It's been going for about a year, and gets misted 2x/day with a fan and a grow light. Some of the plants are even growing and putting out roots. (Yay!)

I recently replaced my Dendrochillum parvulum (one of my first orchids, so subject to a couple of experiments... thus the need for a replacement). It came with a Dryadella pusiola and a Maxillaria schunkeana. Everybody just came out of quarantine.

The Dendrochillum and Dyradella were isolated together, the Maxillaria separately after the first couple of days. In the first few days, I saw a little white mold on the Dendrochillum's stick and a touch on the Maxillaria's stick. After that I kept an eye on the watering and the rocks / moss that they sat on.

Isolation ended on the 3rd, so this morning I went to put the Dendrochillum and the Dryadella in the terrarium. The Dendrochillum now has more mold, but the other two seem fine.

Now for the question:
My understanding is that the mold is a sign of (bad) conditions, but shouldn't actually hurt the plant. But I don't want to introduce mold into the terrarium... so what can I use to get rid of it? I have some neem oil; I have isopropyl alcohol; a mix of garlic, mineral oil, and water; and hydrogen peroxide. I even have Listerine. I probably have a couple other things that I bought and never used.

I've attached a couple of pictures of the mold.

So, help! I'd really like to get the Dendrochillum and Dryadella into the terrarium, because the misting / fan / light conditions are much more controlled there. Not so much in the isolation tank.

	Mistking Looking for a misting system? Look no further. Automated misting systems from MistKing are used by multitude of plant enthusiasts and are perfect for Orchids. Systems feature run dry pumps, ZipDrip valve, adjustable black nozzles, per second control! Automatically mist one growing shelf or a greenhouse full of Orchids. See MistKing testimonials

[Ray]

Mold is ubiquitous. The stuff on the wood slab is decomposing the long-since dead tissue.

That said, the high humidity and temperature in the tank are probably the factors supporting the mold growth. As you want to maintain the humidity, creating some air movement might mitigate it somewhat, but probably won’t eliminate it.

A treatment with a disinfectant would likely work, but only temporarily.

This is a total shot in the dark, but have you considered applying a plant probiotic? Some contain bacterial that predate other bacteria and molds, or secrete antibiotics that prevent their growth, so it might be worth trying.

[OrchKid]

Originally Posted by Ray

Mold is ubiquitous. The stuff on the wood slab is decomposing the long-since dead tissue.

That said, the high humidity and temperature in the tank are probably the factors supporting the mold growth. As you want to maintain the humidity, creating some air movement might mitigate it somewhat, but probably won’t eliminate it.

A treatment with a disinfectant would likely work, but only temporarily.

This is a total shot in the dark, but have you considered applying a plant probiotic? Some contain bacterial that predate other bacteria and molds, or secrete antibiotics that prevent their growth, so it might be worth trying.

Thanks for the quick response, Ray!

The isolation tank actually has a fan, but because it's much smaller than the terrarium and the mister is a human the conditions are definitely not well-controlled.

So it sounds like the possibilities are
1 - probiotics, and/or
2 - putting the Dendrochillum in its own environment (not a biggie; still have glass containers from pre-Exoterra experiments). I can nab the secondary fan I'm using in the isolation tank, so just have to figure out a good way to raise the humidity and rig decent lighting.
OR
3 - taking the 'chillum off the mount and remounting it on something new. THAT (at least, unmounting) is the basic reason I lost the first one!!!

If I put it into it's own environment:
- can I use live sphagnum in the container (I'm getting some for a separate experiment, likely this month)?
- will the mold eventually "grow itself out" - as in one day I can put the Dendrochillum into the terrarium with no worries?

And what do I look for in a probiotic? (P.S. - just found the probiotics article on your website, so reading it now. )

===============

Just to add - this is a bit of a disappointment, as part of reason for the second Dendrochillum was to see if the terrarium would fix what I did wrong before.

[estación seca]

Fungal spores are everywhere, in every cubic millimeter of air, on every object, including inside your terrarium, and on every square millimeter of your skin. It's impossible to keep spores out of or off of anything.

Whether they grow depends on ambient conditions. Whether they infect plants depends on the health of the plant and the species of fungus. As you mentioned, many fungus only grow on dead plant material.

The way to prevent fungal and bacterial infections is to have healthy plants less susceptible to disease; to have good air circulation so spores are less likely to land on plants; and, to maintain humidity no higher than necessary for healthy plants, because fungi are much more infectious in higher relative humidity. Probiotics have been shown to prevent infections but they can't make up for inadequate growing conditions.

Most homes outside the wet tropics don't have high enough relative humidity for fungus to attack plants. Most growing problems and leaf spotting in a home are due to inadequate growing conditions, not infection. Inside a terrarium it is different. This is why air circulation and air exchange is so important. The relative humidity shouldn't be kept higher than necessary.

The way to have healthy plants is to maintain proper growing conditions. When temperatures, light, humidity, watering and nutrition are good, plants are far less susceptible to diseases. The use of probiotics on healthy plants makes them even less susceptible.

[Blueszz]

What about the use of springtails. I know several people that use them in a terrarium with frogs, to combat mold.

Springtail - Wikipedia

[Canadienne]

My Orchidarium is gonna be up and running next month, and I will use springtails, they eat mold ( if it gets that far). I have built it in a large aquarium, has fans and led grow lights. Now hope it’ll all work.

[OrchKid]

Thanks everyone for the input! very very helpful.

I'm still concerned about introducing this particular mold into the terrarium, so I'm planning to take the new terrarium route with the Dendrochilum (and I suppose the Dryadella). I'll try a probiotic and see if that makes a difference; and, if the mold gets out of control, there's the springtail option.

Ah, experiments... Brings out the inner Frankenstein.

Now to turn thoughts on the setup into reality.