Depends on where you live Joe. When I googled Dry Stall for NewZealand all I got was about pigs..... Nothing to do with the stuff we are thinking of. So pumice it has to be, although I also bought some baked clay kittylitter today. And will check what they sell for hydroponic gardening. Ina On 3/07/2013 4:24 p.m., Joseph Kraatz wrote: > Dry Stall is supposed to be large. Little smaller than a pea. It is made for horse stalls. It would not be useful if it created dust when the horses walked on it. Joe -- Ina Crossley Auckland New Zealand zone 10a