New Tank Very Cloudy

I am just starting a tank - no fish or corals yet. I got everything
set up and running, then added 20 lbs of Garf's Grunge. For the next
12 hrs, I couldn't see more than 2" into the tank. After, things
settled a bit, but the water is still quite cloudy, nothing like what I
had before I added the Grunge. I have no external filter to help clear
the water, although I borrowed a hang-on-the-tank filter temporarily
from a freshwater tank. Judging from the amount of stuff caught by the
filter, most of it is just settling to the bottom of the tank. If I
reach in and disturb the substrate, a silt cloud takes over again.

Do I just wait it out, or is there something else I can do? Thanks.