Fresh Rice Hull (Ipa) 5L by Plant Culture PHFresh Ipa are the hard protecting coverings of grains of rice. In addition to protecting rice during the growing season, rice hulls can be put to use as building material(great addition to soil quality, perfect for your cacti and succulents allows drainage, aeration and retains less water than stones, insulation material, or fuel. Rice hulls are part of the chaff of the rice). Approx. 1 liter (700 grams)