Pool water smells rotten

-Hi,

My pool was opened up today (covered in winter by opaque plastic cover) and the water stinks, like a rotten smell. It's also pretty cloudy, I can see to the bottom but it's cloudy.

Any ideas on what to do? Take a sample to my local pool store this weekend if that's the best corse of action.

It's a salt cell system. Would adding salt and running the filter clean it up through producing more chlorine?

Thanks