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, as well as other secondary treatment systems, and is recommended in aeration systems that are prone to backup. It is quick and easy to install and requires minimal maintenance. It is available in several models. 800/536-5564; www.retro-air.com.