Cool approach to estimating the lift rate, Journey! I like the idea of oversizing a system just to cover all the assumptions that we make while designing...moving water in a pond is not an exact science.
Jumping back a few posts...
I pulled my 3 vertex diffusers (9" dia) yesterday to clean them and relocate them slightly. After they were cleaned and just sitting in the open air, I remembered this thread and turned on the compressor and completely opened the dump valve. Unfortunately, the dump valve could not relieve all the airflow, so all I could get was a point of reference. All three diffusers were swelled and passing air and the pressure gage was reading just slightly over 1 psi. I know that it takes less than 1.25 psi to operate a Vertex diffuser. Probably much less if we consider the line losses that would be included in my "test". I will continue to use 1 psi for calculation purposes.
