RE: Dealing with sand
I would just go ahead and wash it and kill the bacteria in it and start over from scratch. I've done this before with "recycled" sand with no problems. Its a lot of work though. Just keep stirring it and pouring off the silty, brown water. I then spread it out on my drive way on some plastic sheeting to let it dry.
When you get ready to get the tank back up and running, just re-seed it with some donated sand from other folks. Some reef grunge from GARF is also good to help it get restarted.
Gary
125 SPS, 75 gal. LPS/softie reef, 9 gal. Nano