A very odd question

[marcingo]

When I was getting the sand from the tank I got it from we smelt the rotting egg smell and the guy told me its h2s he had a 3-4 inch sand bed in his tank. I put the sand in my tank so it has mixed most likely. So if its in my tank water does that make the water unsafe and do I have to remove all the sand clean the tank and throw out all the sand and go out and buy some new stuff? Or will it eventually leave the tank. Everytime I go back in the room or spend time there I do get the burning sensation very similar to the one you get when you ingest chlorine or salt water through your nose in a swimming pool.

I guess my question is if it is h2s will it leave the tank and is the sand fine to keep as long as I moved it all around or should I get rid of it. Thanks.