Rhino Skin contains silica, which is the second most abundant element in the earth's crust (oxygen is the most prevalent) but guess what? Silica is missing from hydroponics root zones and fertilizers. Plants evolved to intake Silica so it becomes part of their cell walls. That's important because cells are the building blocks of your plants and cell walls are the structural features that determine the strength of your plants' stems leaves flowers floral structures and metabolism. In fact your plants contain as much as 10% of their weight as silica.The team at Advnaced Nutrients experimented with many different types of silica, as well as different concentrations and manufacturing methods. They found that the form of potassium silicate used in Rhino Skin produced the highest crop silicate percentages.