... ,reusable,biological. 2. save water & nutrient SAP for agriculture and gardening, super absorbent polymer,water absorbent polymer:can swell hundreds ... with soil or substrate to preserve water and nutrionts,small plants, agriculture and non-soil transportaion.There are 4 sizes, ... "for details)Packing:20kg/bag25kg/bag SAP for agriculture and gardening, super absorbent polymer,water absorbent polymer