Is this a new tank set up? If so your tank will need to cycle. Adding the sand will only aid in the cycle.
But
If your trying to transfer from another tank or have cured LR I would recommend killing the sand 100%. Rinse it really really well in fresh water (until the water runs clear) and eliminate any possibility of contamination.
Don't worry it will be alive again before you know it
Here is a pic of my dead tank after transferring sand unrinsed for a health tank
Before
