Check the listing for details. Humboldts Secret Tree Trunk - Silicate Additive - Advanced Nutrients Fertilizer. Condition: New, Made in USA. Listed at 24.57 USD. PREMIUM POTASSIUM SILICATE-BASED PRODUCT: Tree Trunk features advanced nutrients that will help the plants natural ability to strengthen its cell walls, resulting in thicker stalks and better branch development, as well as abiotic stress tolerance! PLANT STRENGTH: Watch your plants grow by applying Tree Trunk liquid fertilizer. Hydroponic nutrients make our product suitable as quality indoor plant food. ABIOTIC STRESS TOLERANCE: Tree Trunk is needed to ensure yield stability under abiotic stress and minimizes the environmental impacts on crop production. COMPATIBLE IN ALL GROW MEDIUMS: This formula makes for an excellent indoor plant fertilizer suitable for all grow mediums. The usage rate is between 2.5-5ml/gallon (5ml is approx. 1 teaspoon) throughout the entire grow cycle. THICK STALKS & BETTER BRANCH DEVELOPMENT: Our healthy liquid fertilizer will help your plants natural ability to achieve sturdy, thick silks as well as strong and abundant branches.