P4 Water Storing Granules P4 is a must for every pot, and it's great in flower beds, too! Best defense against drought, neutral in pH and non-toxic, P4 reduces the rate of soil water loss by evaporation and drainage, and improves soil quality. In sandy soils, P4 increases water holding capacity by 600%! Mix 2 lbs. P4 with one cubic yard of potting soil. For existing plantings, make several small deep holes in the soil at the base of the plant and add a teaspoon of P4 to each hole. Water thoroughly. Granules absorb hundreds of times their weight, and after a few days, plant roots will migrate to the thousands of tiny reservoirs and attach themselves. Watering frequency can be reduced by 75%, ensuring that plants are always moist while at the same time saving expensive water. K105 P4 Water Storing Granules, 5 lbs, $44.95 P&H $5.50 Quantity to order: