[caferacermike]

Live sand is important. Many of your critters may still be alive. Was the water left in it? Was it salt water? Was the jar open or closed? Pour the sand and water into a bucket, smell it. If it smells like death it is ruined. You can rinse the sand out in clean water until the smell is gone and continue using it but the benefits ar gone. It will however quickly reseed into new live sand.

 

[caferacermike]

Most likely it will give you troubles then. You'll need to do a lot of water changes and wait a long time for the tank to cycle, unlike if you had used a clean sand. In the end it will probably work out, just takes a long time.