Moved tank, lots of settled grey stuff on sand bed now, help

[napydred]

I Just got a 55 galon tank. it was already established. The sand bed was stirred up when i put new water in it after the move. Now all this crap is settling on top of the sand bed. It is ALOT of settled grey matter on top of the sand bed. Any suggestions on how I remove this would be much appreciated.

 

I have some rock, skimmer, wet dry, but I haven't turned it on yet. Should I remove this settled crap before I turn on my tank or go ahead and let the tank try and clean it up?

 

 

Thanks for the help.