I recently learned something about the Eco7 pumps. An air flow guage was hooked up to an Eco 7. At open air flow, no back pressure resistance, the pump did great, even excellent producing 5-6cfm which is a very good impressive amount of air flow. Then the air flow was restricted to simulate water depth, as the resistance approached 2psi (4ft depth)the air flow volume dropped way down to 1-2 cfm. As more restriction toward 4 to 5psi was applied and the air flow dropped noticably below 1cfm. A call to the manufacturer and they said they do not have a flow rate chart for the various depths because they make this pump only for aquarium - aquaponics applications where depths are usually 12" to 16" and rarely exceed 2 ft. Greater depths put excessive resistance to the pump's mechanics/hardware. If one would see the size of the boil from an Eco7 and a pump with adequate pressure at 8 to 16 ft deep there is a dramatic difference in the size of the boil and amount of water moved resulting from the upwelling water and surface boil.
Last edited by Bill Cody; 05/20/13 09:08 PM.
