Aquatrols TurfRx Si ACARXSIG2X2.5 2.5 gal Fertilizer 2 per Case. TurfRx Si is specifically formulated to provide efficient calcium and silicon nutrition. Silicon enhances the proper uptake and organization of calcium for cell wall structure. Lack of calcium and silicon nutrition leads to abiotic stress and cell wall degradation. Enhancing cell wall structure will reduce ball markings, improve ball speeds, and improve overall playing surface performance. TurfRx Si is unique in its ability to improve Abiotic Stress Defense.