We used sodium benonite last summer in a friends pond.We had a very dry summer and it was totally dry.Brought in a excavator to widen and clean up the pond and then treated with the benonite.About 50
50# bags($15/ea) for a pond about 30'x60'x10'average depth.This was done in August and the pond is just about full with the rain/snow we have had this fall and winter.
Also called drillers clay.Time will tell how well it works but looks encouraging.
I'm curious too. One thread I found that looked promising, guy tried it in 2014 and said he'd write a long term review - stopped. Someone asked for an update in 2015 - nothing.
Here's a similar product that may be cheaper:
Corporate Account Liaison
Technical Rep
Aqua Ben Corporation
Hydrosorb, inc.
A division of Aqua Ben Corporation
1390 N. Manzanita St. | Orange, Ca 92867
cell: (619) 312.7777 | fax: 714.771.1465 | email: smiller@hydrosorb.com | smiller@aquaben.com