I think I just contaminated my whole growing area with Erwinia...

[Idril]

Hi, I'm new to this forum and to orchids. 2 weeks ago I rescued 2 orchids with severe root rot from somebody. I did a lot of research and things were going well, but a few days ago one of my plants got bacterial soft rot on one leaf. I cut that part off and that leaf is still fine, but today I found another leaf with a much bigger rot. I removed the whole leaf but I'm still not sure if I was able to stop spreading the disease. My other orchid is fine, besides the fact that it has no roots, but that's another story.
If these plants don't make it, I will want to buy a new, healthy plant. But I live in a small apartment and I only have a tiny place where I can grow plants, so the new orchid would have to live where my current ones live. Would it be in danger of soft rot because of the diseased plants even if I wait a few weeks in between plants? Other question is that I used to soak the one that got sick in the fish tank. So I guess now the water is contaminated? If I use that water on other plants that would be dangerous for them? How long can these bacteria live in water?

[Ray]

It is not wise to ever share water among your plants- precisely because of the cross contamination issue.

How long can pathogens live in aquarium water? It's wet, warm, full of nutrients and oxygenated - I'd bet a while.

[SouthPark]

Originally Posted by Idril

I found another leaf with a much bigger rot. I removed the whole leaf but I'm still not sure if I was able to stop spreading the disease.

For orchid growing, it can help to have an assortment of treatments for fungus/bacteria/mites etc. If you encountered rotting, then a procedure could be to check roots, to see if they're ok, and check to see if you have good air circulation around the plant (including air circulation for the roots in the growing media), and maybe apply some recommended bacterial and/or fungal treatment for orchids to help it along.

Air circulation means ----- adequate moving air ..... even if it is relatively slow moving air.

For the tank or pots, should empty them out and give them a nice spray of sanitising solution, like bleach/hydrogen peroxide.

[Ray]

Since the folks at Inocucor (now Concentric Ag) turned me onto their Garden Solution product - a "plant probiotic" containing a wide assortment of beneficial bacteria and fungi - I have stopped using any chemical disinfectants or fungicides.

Besides killing and devouring pathogens, they exude antibiotics into the potting medium that prevents further infection, and some of them exude a small amount of growth-stimulating hormones.

[Idril]

Thank you for the answers. The root rot occurred by the previous owners. I took them out of the pot, one of them (the rootless) is in full water culture, the other one is gpinv to be mounted when I find a suitable piece of wood, now it's just laying around bareroot. I'm going to try that plant probiotic, does it work without potting medium?

[Ray]

Originally Posted by Idril

I'm going to try that plant probiotic, does it work without potting medium?

Yes, because most of the critters infect the plant, as well.

[Idril]

My plant just got the soft rot the third time. Now it's part of the stem and I can't cut it off. I'm so sad, I don't think there is a way to save it.
The other one isn't infected, but has no roots and not looking good either.