In what seems to be my never-ending quest for pumice in the midwest, I ran across a product call Sweet PDZ which is something like Dry Stall that is sold in Cal. It is a clinoptilolite which is a zeolite. It is used in horse stalls and can also be used in soils. It is a volcanic by-product, retains water and has a high CEC. It also maintains its structure after freezing and thawing. It comes in a granular form. Anybody seen or used this before?