The Retro-Air Rejuvenator System from Septic Services provides a complete drainfield rejuvenation system that returns a failed existing septic system back to optimal flow and performance, according to the maker. It can be used in new or existing septic systems and can be installed in single or multiple-compartment septic tanks. It helps eliminate clogged drainfield biomat and is recommended in aeration systems that are prone to backup. It uses the aerobic process to restore failed anaerobic installations or to prevent failures in newly constructed systems by delivering a constant flow of air to the diffuser. Over time, aerobic bacteria consume the biomat, allowing the soil to absorb effluent once again. It is quick and easy install, requires minimal maintenance, and is available in several models. 800/536-5564; www.retro-air.com.