> Because rock salt is hygroscopic it absorbs moisture from the air. If your plan is to get rid of the humidity in a damp basement, start with a 50-pound bag of sodium chloride to make your rock salt dehumidifier. These can be found at most big box hardware stores. While you’re there, you’ll also need two 5-gallon buckets. Here’s what you’ll need to do next:
> In one bucket, drill several small holes into the side and bottom of that bucket
> Nest the drilled bucket into the other bucket
> Fill the bucket up with rock salt
> Collected water will drip through the holes in the inner bucket into in the outer bucket over time
> Empty the outer bucket as necessary
> Refill the rock salt as needed
(https://www.reddit.com/r/homestead/comments/wziu44/the_basem...)