Nutrient Control for Fungus & Molds. Adding Potassium Silicate to your nutrient solution helps prevent the growth of mold and fungus in plants, helps raise the pH of the nutrient and is a source of potassium for your plant. Rambridge Potassium Silicate mix is 16 times more concentrate than any other on the market. A smaller amount is required to get optimized results. Potassium Silicate can increase your plants tolerances of environmental stress, temperature changes, water and soil toxicity. It can also aid in the improved growth rate in the root zone and the foilage.