MICROBE-LIFT bacterial products are formulated to work together for the cleanest pond water and healthiest fish and plants. Basically there is no potential for overdose, as it is a beneficial and non-toxic bacteria. However if excess product is added, it becomes less cost effective to the consumer. When there is more bacteria added to the pond than needed, the excess will starve and die off.
The one problem associated with overdosing bacteria, other than economics, is that if there is a lot of organic buildup when you overdose, you can stimulate too much activity and associated oxygen demand, depleting the water of adequate oxygen to support the fish.