What size pump does my pond need?

As a rule of thumb, the pump should move the whole pond at least once an hour, and a waterfall needs about 1,000 to 2,000 gallons an hour for every foot of spillway width, sized up for height and pipe. The free pond planner at pondsbymay.com/pond-calculator/ works out gallons, liner size and pump size, and Ponds By May will confirm it on site.