Skipro, instead of trying to detoxify your nitrites, you should try to eliminate them. A well established tank should never have any ammonia or nitrite (at leats enough to show up on your test kit). This can be accomplished by having an adequate filtration system, such that you have enough beneficial bacteria in your filter to clean out all of these compounds. After that, keep up with the water changes to keep your nitrates and other organic compounds low. Thats the basics of fish keeping, and if you follow that you will have no problems (try to keep a stable pH as well). Basically, add salt if your fish are stressed, if youre having some specific problem, but do not use it as a regular additive. How big is your tank, whats in it, and what type of filtration do you have?