Non-iodized salt is an amazing cure for an extremely wide range of fish ailments. This is a staple item you should always have on hand. An all-natural sea salt that replaces electrolytes, such as potassium, sodium, calcium and magnesium. They are essential for the uptake of oxygen and the release of carbon dioxide and ammonia, which fish lose in times of stress. Temporarily blocks the toxic effects of nitrite. Safe for plants. Use a Salinity Pen to monitor salt levels.