I do have a pressure gauge in my compressor cabinet. It is connected to the manifold that feeds the air to the diffusers.

I have three diffusers running off the compressor - one close, one in the middle and one on the far side of the pond. I give the far one a bit more air than the middle one, and the close one gets the least. They seem to be balanced.

What is the typical pressure reading I should be looking for on the gauge?

thanks