a septic field dosing system is described which utilizes a self starting true siphon to deliver a dose of septic tank effluent into a conventional septic field . the precision siphon unit described by present invention not only eliminates the need for electrical services to the septic tank , thereby eliminating the need for pumps and solenoid operated valves and switches at the septic tank , but also contains the effluent handling equipment in a small unit which uses the available features of the septic tank to assist in the performance of its operations . for example , the drawdown of the septic tank which is now determined by the configuration of the siphon unit is used to entirely control the operation of the dosing siphon . further , the dimensional configuration of the precision siphon taught by the invention operates within the boundaries of the draw down to deliver a proper size dose to the septic field . while a typical septic tank can hold of the order of a thousand or more gallons , the precision siphon can easily fit into a five gallon bucket .