Advanced Nutrients Rhino Skin is a high-performance additive, which contains a unique blend of silica, made specifically for use with hydroponic growing systems. Although silica is the 2nd most predominant element in natural soil conditions, it isn't available in hydroponic fertilizers or root zone. Plants use silica to strengthen their cells' walls. Cell walls determine the strength of your plants' leaves, flowers, and stems. Plants also use silicon as support between their cells. Around 10% of plants' weight is silica. Rhino Skin delivers top-quality and increased amounts of silica to your plants to ensure healthy and accelerated development.