Problem with "Hair" Growing in Arboreal Tank - HELP!


Jan 7, 2007
To house my 1" poecilotheria fasciata I used about a quart size container filled with about 3" of 50/50 peat moss/topsoil I also got some bark off a tree in my backyard which I use for a hiding spot and a climbing area. The bark, peat and topsoil were heated in an oven at 425 degrees for about 1 hour.
At first it was eating crickets. It has since stopped so I thought, maybe its molting. Hasn't molted, still won't eat but now I see this white "hair on only one side of the bottom of the tank. At first I thought it was webbing beacause it is only dispersed on half of the bottom of the enclosure. But now I am beginning to think it is mold/fungus.
Please check out this picture:

1. Is this mold/fungus or webbing?
2. If its is mold/fungus how do I get rid of it?
3. Why isnt it eating? It's abdomen is very small (I received it a week and a half ago in the mail.)
4. It has hid under the small bark hide you see in the pic underneath the "hair". What should I do?

Thanks in advance.
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Old Timer
Jul 22, 2006
Wow that doesn’t look all that good at all. To start you need more air holes around the sides of the container not just at the top. Ventilation is key. I see a lot of mold in there…the hide needs to be removed ASAP. Have you pulled out the crickets that were not eaten? Have you even seen the spider lately? To be honest I would just go ahead and rehouse the P. fasciata there is just too much mold in there. Here is a container I’m getting ready for a new occupant. Notice all the air holes melted in to the sides there are a lot on the lid as well.

Good luck


Old Timer
Dec 20, 2006
i would change all that soil asap. and more holes would help a lot.
try to find all dead crickets too, they can cause nasty stuff to pop up especially in a moist environment


Old Timer
Oct 19, 2004
Dude, that is a lot of mold! Your post says you used topsoil and bark from your back yard. That, combined with lack of ventilation, is probably the problem. Often baking will not eliminate all of the mold spores, and even at that high of a temp, many spores could survive for a short duration like that.

First, you need to get that spider out ASAP. Put him in a totally clean environment until you get the cage reset.

Second, dump *everything* out of that container. Clean the container and lid with a bleach solution and then poke about a jillion holes in it.

Start over with fresh substrate. Lots of people like peat but I find it tends to mold easier than coconut bark. Good luck!


Old Timer
May 12, 2006
I would say lack of ventilation and perhaps a lack of picking leftovers out would be the main culprit. I don't really see mold spores surviving 425* for an hour, but I guess anything is possible.

I would remove the spider from that enclosure and wash it as suggested with a diluted bleach solution, making sure to rinse well. I would also drill more holes in the container for much more ventilation. A few down at substrate level and some up at the top, so it gets cross ventilation.

Replacing the substrate with fresh and ordering some cork bark, which is naturally mold resistant for any moist enclosure needs is always a good bet.

Lots of people use potting soil I've seen, so it may just be that source of soil. I find it funny that someone mentioned peat molding more than coconut, when the pH of peat is so acidic its usually quite fungus resistant.


Old Timer
Dec 12, 2003
Why did you bake the peat and top soil? The bark I can understand because it came from your yard but what kind of bark was it? When you bake bark, first make sure that the bark you are using doesn't have anything on it. Scrub it under hot water first, then bake it at a low temperature, about 200 F. for about 20 minutes. The problem with baking at high temperatures and/or for long periods of time is that not only do you kill the bad bacteria that causes molds, fungus and such, you also kill the beneficial bacteria that prevents its growth. So basically, by baking it that long at that high of a temperature, you rendered the bark, peat and soil *more* susceptible to molds because nothing is left in it.
Definitely rehouse, clean that out real good with very hot water and vinegar and put a lot more air holes in it.

I've rarely ever had a problem with peat molding in high humidity containers. Cork bark though, that stuff seems to go in spurts. Sometimes it doesn't ever mold and sometimes all it does is mold up.