RAW Silica contains 45% Silicon Dioxide which is the highest concentration of silicon dioxide available to the home gardener. RAW Silica is flowable and suspend-able in water and naturally available to the plant. Since RAW Silica is a natural form of silicon dioxide, it is PH neutral and does not cloud when added to water. RAW Silica can be used during all stages of growth and bloom for optimal stem and cell wall strength. It is a beneficial supplement to all feeding schedules. Works in conjunction with all nutrient and feeding programs.