A method is provided for clarifying a flowable starting product with a separator having a feed and at least one liquid discharge for continuously discharging at least one clarified liquid phase—a clear phase—and with discontinuously openable solid-discharge openings for discontinuously discharging the solid phase. The method involves the steps: a. setting or determining a starting time; b. repeatedly determining at least one actual value of a product-parameter of the clear phase derived from the drum; c. determining the time interval until the product-parameter actual value reaches or exceeds a product-parameter limit value; d. preferably initiating a solid discharge as a result of reaching or exceeding the product-parameter limit value; e. determining and setting an operating time interval by using the determined calibrating time interval, the operating time interval being less than or greater than the ascertained calibrating time interval; and f. initiating at least one or more solid discharges each time the set operating time interval has elapsed.