Quick question!


Mar 27, 2017
Hey, guys! Thanks for taking time to read!

Is it safe if I substitute the substrate for sphagnum moss for my OBT and versicolor slings?

I have OBT slings (size ranges from .75"-1.5") housed in small snap cap vials. They have molted numerous times so far, and it's incredible how sturdy and fast they are growing. I aim to transfer them into AMAC boxes real soon. The containers are taller than it is wide. Soldering iron is used to drill holes for cross ventilation.

I also have versicolor slings that are 0.25"-0.5" in size. I bought smaller AMAC boxes for them also.


Old Timer
Dec 8, 2006
I use coco fiber for all my Avics. You will find that better to use than moss. Prey items will hide under moss, Ts may not detect them as well. Once a prey items finds a cozy spot, they tend not to move, even w/coco fiber.

Also, when Avics drop their boli down, with moss you are less likely to see it, it will get moist at some point I suspect, and grow mold and/or attract mites IME.

0.25" is pretty small for an Avic, so is 0.5", you will have to pay extra attention to them, and feed them VERY often to keep up their abdominal size, and indicator of their hydration (but not always- esp w/Avics that are 2" and larger). You must provide a water bowl for them too.


Staff member
Feb 22, 2013
Well, I have a question for your question. When you say sphagnum moss, are you talking about this stuff that just looks like dried out moss? Or are you talking about this stuff that looks like fine dirt?

The latter is sphagnum moss that has been ground into basically dirt, and it works perfectly well as substrate. Poor water retention if you ever let it dry out, and it's also quite dusty. It does shrink over time if kept bone dry, leading to a noticeable gap between the substrate and the enclosure. I mix this with topsoil for my substrate.

The former is just dried moss, and shouldn't be used as the only substrate. Some people mix it into another substrate (like topsoil) for water retention, but tarantulas don't seem to like walking on raw sphagnum moss.