The product description does not specify a precise dosage, which is common for bath salts meant for sensory experience rather than targeted treatment. A typical approach is to use a few generous handfuls (e.g., 50-100 grams) per standard-sized bathtub filled with warm water. The 500g format indicates it is intended for multiple baths, not a single use. You can adjust the amount based on your preference for scent strength and the mineral richness of the water; the sea salt base is noted for making the water feel richer and more enveloping. One pack could reasonably provide between 5 to 10 baths depending on your usage. It's a practical size for trying the product over several weeks. For storage, keep the bag tightly sealed in a cool, dry place to prevent clumping and preserve the aromatic properties of the fir components.