Grotek Gro-Silic, 1 LiterGrotek Gro Silic is a concentrated liquid silicon supplement suitable for soilless and hydroponic systems. This plant available form of silicon helps improve plant growth and quality, in part by hardening cell walls. Plants with improved cell wall structure are better able to endure periods of abiotic stress such as high temperatures and drought. Silica is one of the most interesting supplements to add to a nutrient program. While not considered