Negative Feedback, the leaky tank: For a leaky tank, with a lifetime of 10 minutes, the outflow rate is 1/10 th of the volume. If the tank has 10 gallons in it, the outflow is 1 gal/min, and if the water volume is 5 gallons, then the outflow is 0.5 gal/min. This negative feedback is graphically shown in the diagram at left.