The Fusion Series drop-in wastewater treatment system from Clarus Environmental is designed to use anaerobic and aerobic zones to produce secondary-quality effluent. Filter media are never removed or replaced. Features include constant recirculation of treated wastewater and a twice-daily automatic backwash cycle that returns residual sludge to the head of the system. A programmable compressor delivers oxygen to aerobic zones, using about the same energy consumed by a 65-watt lightbulb. 800/928-7867; www.clarusenvironmental.com.