Now there is a device called Tech7 that is currently being sold to the WFP window cleaning market which supposedly lowers the surface tension of water. It also has a filter that removes dissolved solids at the same time. There aren't any pellets or a membrane. The Hydronix CB-25-1005 filter from Chino Hills CA is really not that special. The link for the filter that Tech7 uses is http://www.hydronixwater.com/
Here is a video I pulled up made by Hydronix.