Red Flint Sand and Gravel has produced high-quality filter media since 1917, specializing in low uniformity coefficients and sizes from 2-½ in. gravel to 0.20 mm sand. Anthracite, garnet, Greensand Plus, and granular activated carbon also available. Exceeds AWWA B100 requirements and NSF/ANSI Standard 61 certified. Our engineering staff will review proposed specifications, offer feedback to optimize project’s media requirements, and provide on-site media installation supervision. Same day quotations. International shipments.