Derived from multiple sources of phosphorus and potassium, PK spike is designed to help facilitate bulking and ripening of many flowering plants. PK Spike is engineered to provide a uniform quantity of phosphorus and potassium to your flowering plants. Designed with over 25% more P/K than the next industry leading competitor, this product can be applied at a maximum rate of 1.0 ml/L to achieve a 250 ppm boost to your plants.