While with a buddy helping him pick up pool chemicals for his job at the pool place I happened to see pallettes with 45lb. bags of hypo. They were labeled Prismatic photo rice crystals! It cost me 35.00 for the bag. No shipping either. So look for a pool supply company cause they use it to de-chlorinate pools if the chlorine level went to high and also it is sold to water treatment plants as well. There is usually a pool supply house in every semi-large town. I try to use Mike @ Artcraft for everything but this is just to good of a savings to pass up. Hope it helps. Best, Mike Pry