Frist, I welcome any suggestions as to another or better place in or outside, of YT to post this quarry. I need to signal via an on-off float or pressure switch; when cattle tank level or water pressure reaches a preset minimum level. My first chose is to use a wireless system with a five-mile range. Second chose is a visual system, electric signal light or mechanical flare, observable at one-half mile. I am seeking design suggestions and help to accomplish this. A 12-volt automotive battery will be available to supply power for the mechanical or electric signal. Thanks for all help.