i think the first thing to consider is why you added this to your tank?
salt can be used for treating fish of some diseases, with no fish in though there's no need to add it.
this is one of the first and most important lessons in fishkeeping, do not just add whatever you get supplied with the tank or what the fish shop tells you to add, you should always do your research and find out what the purpose of it is and then make a logical descision over what to add. there are a lot of quite frankly useless products out there and adding them all will do mroe harm than good.
now to get rid of it just do a load of water changes, take water out, add fresh dechlorinated tap water, keep doing this every day and after a few days it'll be so diluted that it's basically gone.
now, second most important lesson is that just leaving the tank for a week will do nothing to prepare it for fish, you need to learn about the nitrogen cycle, how this affects the fish and your choices for completing it. Have a read of
this topic which explains the nitrogen cycle and will tell you what will happen if you add fish now, then have a read of
this topic which tells you about fishless cycling.
few important lessons to learn there, sorry that's a lot of info to bombard you with but it's for the good of your fishies and to make your life as a fishkeeper much easier and calmer!
