The model ELC-810 Automated Water Level Controller is an interactive, fully menu-driven, automated multi-level-sensing control system designed to maintain precise water levels for commercial and residential swimming pools, spas, fountains, and water features. Unlike systems that use floats or other moving parts or introduce an electrical current into the water; the ELC-810 uses proximity sensors to monitor the water level accurately and to automatically activate the auto water make-up control valve. It offers single, dual or tri-level sensing for normal, alternate, and high water levels;integral time delay sequence to avoid cycling due to wave action; and an adjustable feed alarm timer, which interrupts water flow in the event of a problem. in most cases the ELC-810 can be easily retrofitted to an existing pool, spa, fountain, spray ground, or other water feature.