Abstract: A control system monitors salt level in a brine tank having a water inlet. The control system comprises a memory device storing an amount representing actual salt level in the brine tank. A sensor determines water level in the brine tank. A control valve is operatively connected between a water supply and the water inlet for controllably supplying water to the brine tank. A logic circuit is operatively connected to the memory device, the sensor and the control valve for determining salt level in the brine tank. The logic circuit periodically operates the control valve responsive to sensed water levels to fill the brine tank with water, updates the stored actual salt level in the memory device responsive to water supplied to the brine tank, and provides an indication when actual salt level in the brine tank falls below a select salt level.

Abstract: An apparatus for converting a typical anaerobic septic tank system into an efficient aerobic treatment system for treatment of liquor containing biodegradable wastes. The apparatus includes a collapsible reactor module that can pass through a relatively small opening in a septic tank cover. The reactor module contains media through which liquor to be treated is recirculated and aerated.