Chemboys - Silicic Shield (Bioavailable Silicon) 1 Quart (32 fl oz)Chemboys Silicon Shield (Bioavailable Silicon) 0 0 1 is a powerful concentrated silicic acid product formulated to improve plant structure, promote cell wall strength and increase your plants ability to withstand environmental stress. It is 100% soluble and is compatible with all growing mediums. In nature, microbes in the soil slowly break down silicon into a plant available form known as Monosilicic Acid, but in a controlled garden environment this