The 40SQF-5 pump is an extremely high volume pump that is capable of pumping 70 gallons per minute at 6 ft. of lift or 30 gallons per minute at 90 ft. 

Reading the flow charts: Note the gallons per minute on the left side of the chart, find your water depth on the top of the curves.  Follow the curve down to where it intersects with your desired amount of flow line coming from the left.  Where the flow curve intersects with the volume line from the left come straight down to the required amount of watts to make the pump preform that volume. The watts are along the bottom of the chart. Don't follow the curve in the line coming down, you must come straight down from where the lines of flow and depth intersect. You will always want to round up to the next higher wattage system when the numbers for watts required don't match our systems.