Roots Organics HP2 liquid is a specially extracted natural source of organic phosphorus. Phos rock is renowned as a source of available natural phosphorus for use during flowering and fruiting. Aurora Innovations has taken generations of gardening experience and distilled it into a unique, easy-to-use formula for the hobbyist and professional gardener. Roots Organics HP2 is minimally processed to preserve all of the benefits and amazing nutritional qualities found in our biogenic phosphate rock.