I just seen this is another post if this helps any.
EDI 7"(measurement taken from the membrane diameter) Standard diffuser design flow is 0.5-2.5 SCFM with an overall diameter of 9" or 229mm using an EPDM membrane.
Vertex 9" diffuser ( measurement taken from the overall diameter) design flow is 0.5-2.0 CFM using an EPDM membrane.
