Also I have no fish right now so that is why I am asking now before I get anymore. But from the sounds of it I should change out the water in the tank to remove the salt that I added?
This post by liv2padl and ones following it in that thread specifically say tetras like lower disolved solids. I would not use salt at all, and skip the water softener completely. I would treat with a conditioner like Prime anyways just for piece of mind.
No, I keep saying drop test kit. Although I only have the ammonia and nitirite test kits I am going to buy a ph test kit today.
You add fish when the tank is cycled /ammonia- 0 ,nitrites 0,nitrates 0-20(10 is a very obtainable number).Tha ammonia and nitrites should stay at zero.If the nitrates go above 20 the water is becoming stale and polluted and is a breeding ground for bad bacteria and parasites.Fish tanks are very very small eco- systems.
Ph is another test to be done.Rocks with calcium will drive ph up ,wood will lower it.Wide range ia usually acceptable 6.5-8.4 but it is important that it remains stable from week to week.Fish do have preferences to ph,neons would not do good if the ph is too high.Research the fish always be fore buying them,