Hmmm....I'm not that familiar with the product, so not sure what all is in it? Carbon and ion exchange resins I think. I don't understand the use of the ion exchange resins for salt water applications - that would be similar to hooking tank water up to a DI filter. Perhaps siphon out what you can from the fuge. I will move this thread into the chemistry forum, so our chemistry gurus can have a peek.
I used chemi pure for a long time with my first tank. I never ever had any "black soot" to come off of it. Did the bag possibly break, or tear? I rinsed mine really well under just plain tap water (at the time that is all I had) I stoped using it and now I am a big fan of purigen by seachem. It seems to work alot better, last longer, and is regenarble. Much more cost effective as well. I would try to remove as much dust as possible if it were my tank. I dont know that its bad but I cant think of a way that it would actually be good for things so I would try to siphon it out if it were mine. HTH Steve
Good news after cleaning the filters in the refugium all day yesterday and the skimmer working overtime when I arived home today tank was crystal clear I rinsed the chemi pure bag for about 20 minutes and everything is still AOK. Thanks for the help Guys . Is there a better carbon to use other than Chemi Pure I have the bag sitting underneath the return from my tank on the Bio balls should I place it in the sump where its a little bit calmer?