I have been reading through the Adaptive Payment API documentation from PayPal's developer page here, but I have not seen any indication of when the receiver would receive their funds.
Salt is, of course, the most common substance found in sea water, but it is far from being the only one. In fact, sea water is actually quite rich in mineral solids. The solids dissolved in sea water vary from about 1 per cent where rivers enter the sea to about 4 per cent where the circulation of water is partly restricted, but they average about 3.5 per cent (one hundred pounds of sea water, if boiled away, will leave behind close to 3.5 pounds of solids). Most of this is ordinary salt -- sodium choloride.
If water has a concentration of 10,000 ppm of dissolved salts, then one percent (10,000 divided by 1,000,000) of the weight of the water comes from dissolved salts. One good method used to desalinate seawater is the reverse osmosis method. By the way, ocean water contains about 35,000 ppm of salt.