Ted Lea will also advise with this. The increased pressure of both the V.diffuser and stone could be due to a kinked air hose or blockage in the hose. You may have kinked the hose under water. Something is causing restriction of air flow, thus increased pressure reading. Take the diffusers off the hose and see if the psi is 0 with hose end out of water. It should be 0 or very close to it. Figure out what is restricting air flow and you will solve your problem. A dual V.diffuser assembly should easily handle 4.5 cfm. Although at 7 ft deep you will probably not be producing 4.5cfm, more closer to 3.8-4cfm. CFM at various depths will depend on type of compressor.
Last edited by Bill Cody; 04/27/14 01:51 PM.
