Activated Charcoal source

[drsue]

I'm new and have been playing around with plant tissue culture. I've done node cuttings from phals as well as vanilla stem cuttings with reasonable (sterile) success.

I wanted to add in activated charcoal into some of my tissue culture vessels but mine is not fine enough and sinks to the bottom.

Anyone have sources for this? Caisson doesn't have just charcoal.

Thanks

(edited to clarify looking for ultra fine charcoal for tissue culturing)