Black rot in terrarium, how to get off of background

[Fishkeeper]

I have what looks and acts a lot like black rot in my micro orchid terrarium. To get rid of it, I have a pair of sharp scissors, a lighter to sterilize the scissors, and a large jar of ground cinnamon.

I plan to take each orchid out, remove all the moss from them, and cut off the rotting parts, sterilizing and cooling the scissors between cuts. I'll cover the cuts in cinnamon, then set them up in a temporary terrarium, not touching each other, on fresh sphagnum. Hopefully that'll get the rot out of the orchids.

My question is, what do I do about the background? I'll be replacing the sphagnum, but I have cork bark and Hygrolon (plastic mesh that acts like sphagnum) in there as well. Is there any way I can get the fungus off the background, preferably without taking anything out of the terrarium? Will it die off with no hosts if I take the orchids out? Can I get it off with cinnamon?

[estación seca]

It's probably not fungus, but rather algae. Don't bother with your planned intervention. It won't help. Algae grows when conditions are too wet and nutrients are plentiful. Try to give better air circulation, don't keep it so wet, and fertilize a lot less.

[Fishkeeper]

It's definitely not algae. I know what algae looks like, and algae doesn't spread up from the base of the leaves and kill everything it touches.
It started on an H. odonata that got too wet, and killed two formerly healthy adult plants in less than a week. Granted, they're tiny plants, but still. This moves fast, starting at the bases of the leaves and spreading up, and turns the leaves a dark grey-black as it spreads. Any leaf I touch that's infected falls off with no pressure whatsoever.
It's on a bulbophyllum clump and a mini dendrobium now, or at least it was before I trimmed them. Hopefully that got rid of it.

I'll definitely be keeping things drier once I'm sure it's off those plants, I think it was a bit too damp around these two, but it's definitely not just algae.

[Laticauda]

I've been known to use bleach on black mold.

You can also leave it exposed to the sun for a few weeks to disinfect it.

If you do use bleach, I recommend submerging it in (diluted) bleach solution for 30 minutes then submerging it in a bucket of water with 5-10x the recommended dose of aquarium dechlorinator (my personal preference is called Prime) and leave it in there overnight then let it air dry.

That's similar to what a certain Living Museum does to disinfect animal enclosures/accessories.

If you can get a hold of some chlorhexidine solution, that's also antifungal but can be a little hard to find if not cost prohibitive. Its also normally colored blue so there's that lol

[Optimist]

I think what is being said is that the culture (terrarium) most likely caused it. Overwatering, stagnant humid conditions cause the black rot (Pythium and Phytophthora). Inoculating the plant with beneficial bacteria may help.

I suppose you need to take your terrarium apart, clean the background and then get the culture right for the orchids you put into it.

Ray may have an idea about what you can use to kill it off.

[Leafmite]

I am sorry to hear about your issues with your tank. Years ago, I had a bout of Black Rot and lost many beloved orchids. In my case, Calcium deficiency played a huge role as it made the orchids very vulnerable. If you don't have a source of Calcium for your orchids, it might be worth contemplating. I have been trying Osmocote's Flower and Vegetable Slow-release fertilizer as it contains Calcium yet is guaranteed not to burn. I figure if it has enough Calcium for tomatoes, it might work. So far, the Draculas, Lepanthes, and Lepanthopsis seem to be tolerating it very well. I cannot say how effective it is otherwise.

Again, sorry to hear that you are going through this. For me, it was a nightmare. Good luck!

[Optimist]

I'm pretty sure you will need to take everything out in order to clean it. You would kill the orchids if you get cinnamon in their roots. Cinnamon is not a cure-all. It is for deep wounds in healthy orchid tissue, like if you need to cut a leaf or bulb in half. It cauterizes the cut. Bleach will kill your orchids too unless it is a minute quantity.

[Paul]

Is your terr closed and do you have a source of air circulation?

[Ray]

Originally Posted by Optimist

..... Inoculating the plant with beneficial bacteria may help.

Ray may have an idea about what you can use to kill it off.

Inocucor Garden Solution is an engineered blend of beneficial fungi and bacteria consortia that is intended as a plant probiotic, but I have used it as a curative measure on plants with great success. I have never considered it as a treatment for an enclosure, but it makes decent sense.