Determining Pump Size

Rectangular Shaped Ponds

The size of a pond pump is determined by (1) the size of the pond, (2) how high the pump must pump water and (3) how much flow is needed for a stream or waterfall. Knowing the size of the pond is important, because a certain amount of water circulation is necessary to maintain pond health. To compute the number of gallons in a pond, multiply the average width by the average length by the average depth to get the cubic feet, and then multiply the cubic feet by 7.5 to get the approximate number of gallons.

AVG. WIDTH x AVG. LENGTH x AVG DEPTH = VOLUME in CU FEET

An example: a 10 x 12 foot pond that averages 2 feet deep. 10 x 12 x 2 = 240 cubic feet times 7.5 equals 1800 gallons.

Circular Shaped Ponds

For a circular pond, multiply the radius (distance from the center of the pond to the edge) times itself times the average depth times 3.14 to get the cubic feet. Then multiply the cubic feet by 7.5 to get the approximate number of gallons.

RADIUS x RADIUS x 3.14 x DEPTH = VOLUME in CU FEET

An example: a twelve foot round pond that's two feet deep. The radius of this pond is six feet. 6 x 6 x 3.14 x 2 = 226 cubic feet times 7.5 equals 1695 gallons.

Courtesy Aquascapes Design Inc.

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