KALIX K-Silicate is 100% water soluble potassium silicate derived from silica and potassium oxide. Silica has been found to strengthen cell walls giving plants an increased resistance to environmental stress. Use as directed as a readily-available source of potassium and silica during all stages of plant growth. Concentrated potassium silicate will react with other elements, so it is best to be added to solution prior to other nutrients - or diluted before adding to a nutrient solution.