coquina sand?

i have a jar of coquina sand from florida that my mom collected when she was little.it's basically crushed shell, i was wondering if it was safe to use in my salt water tank or if it's going to spike my nitrates or something.

 

I don't know what coquina sand is but rinse it very well with some bleach and water, then rinse many times with straight freshwater and maybe some Amquell.

Shells tend to leach phosphates more than sand does. As a result, I would soak it in RO/DI water for a couple of day to leach most of them out. Then use it.

It would be kind of cool to tell your mom that you have her sand in your tank.