When blooming and ripening fruit, good phosphorus levels are very important. Straight from Indonesia, Buried Treasure? Phos Seabird Guano is a natural fertilizer that contains phosphorus. It can be used indoors or outdoors on vegetables, herbs, flowers, ornamentals, and in hydroponic applications. Buried Treasure? Guano is micronized for better solubility and delivery. Does not contain fillers.