The frequency of using hair sea salt spray depends on several factors, including your hair type, the condition of your scalp, and the look you are trying to achieve. Here are some general guidelines:

1. Hair Type: If you have fine or thin hair, you might find that you can use sea salt spray more frequently since it can add volume and texture. If you have thick or curly hair, you might want to use it less often, as the salt can sometimes make the hair feel dry or crunchy.
2. Scalp Condition: If your scalp tends to be dry or sensitive, you may want to limit the use of sea salt spray because the salt can exacerbate dryness. In this case, consider using it no more than a couple of times a week.
3. Desired Look: If you love the beachy, textured look that sea salt spray provides, you might use it every time you wash your hair. For a more polished or sleek look, you might opt for different styling products.
4. Product Buildup: Overuse of any styling product can lead to buildup, which can weigh down your hair and affect its overall health. If you notice your hair feeling heavy or looking dull, it might be a sign to reduce the frequency of use or to clarify your hair with a clarifying shampoo once in a while.

A common practice is to use sea salt spray 1-3 times a week, depending on the above factors. If you're using it on second-day hair or hair that isn't freshly washed, you might also use it more frequently to refresh and add texture. Always remember to follow up with a good conditioner or a hydrating treatment to counteract the drying effects of the salt.

Ultimately, how often you use sea salt spray is a matter of personal preference and should be adjusted based on how your hair responds to the product.