DCT Bio Drain XL is designed for optimal maintenance of environments such as: drain lines, septic systems, grease traps and interceptors, and holding tanks where it reduces build-up, prevents back-up and keeps systems free flowing. The product is especially formulated to reduce suffer gas smell that can come from drains. For drain line and grease trap maintenance, product should be used as a preventive treatment or to increase the rate of flow through drains.