The Retro-Air Rejuvenator System from Septic Services is designed to improve flow and return a failed system back to optimal performance. It delivers a constant flow of air to the diffuser to restore failed anaerobic installations or to prevent failures in newly constructed septic systems. As the biomat in the absorption field continually builds up, it clogs the pores in the soil, causing effluent to rise to the ground’s surface. If allowed to continue, sewage backups can occur. The unit delivers dissolved oxygen and aerobic bacteria in the absorption field. Over time, aerobic bacteria consume the biomat, allowing the soil to absorb effluent once again. It is designed for 500- to 2,000-gallon tanks, and can be installed in single or multiple compartment systems. It includes aerator pod, air line-diffuser assembly, outlet baffle filter and installation manual. 800/536-5564; www.retro-air.com.