To make your own sea salt, all you have to do is collect your salt water and strain it through cheese cloth or a fine sieve (or both).
Boil the water to your hearts content. Technically, you could make sea salt by pouring the water into shallow pans and leaving them outside for the sun to evaporate all the water. But who has the time for that. The boiling time varies depending how much water you collect. I would plan on about spending 1-1/2 to 2 hours per gallon of water. The nice thing about choosing the stove top boiling method is the heat will kill any bacteria which may be catching a ride in your salt water.
When the majority of the water has evaporated, pour the the salt water into a shallow baking pan to prevent the salt from scorching. The salt water should have the consistency of wet sand at this point. Leave the pan uncovered at room temperature for 3-5 days, stirring it occasionally. The remaining water in the pan will evaporate over time.
Once the water evaporates and the salt is fully dried you will have a nice batch of freshly made sea salt. The salt won’t be like the pelleted sea salt sold in fancy stores. It will be more flaky and similar to kosher salt. Be sure to store the salt in an airtight container so it doesn’t pick up any other smells or flavors while hanging out in the spice cabinet.
It will produce 1/2 to 2 cups per gallon.
The teaspoon of water was just to get the system to accept the recipe, you can omit it.