ocean water/air too: http://www.mgwater.com/rod18.shtml
Ocean Water and Magnesium
Mrs. E. Clarke Smith of San Antonio, Texas, writes:
"Swimming in the ocean for several weeks has benefited me so much that I wonder if there could be some absorption of magnesium and other minerals we earth-bound creatures need."
There no doubt is, because seawater is very rich in magnesium. It represents about 13/100 of 1 percent of all the minerals in seawater. This is a large amount. Therefore, by all means, dunk yourself in seawater every chance you get. In fact, merely to be at the seashore and to breathe the magnesium-rich sea air should be invigorating and healthy.