Keith,
I've always heard the same thing about the air gap. The movies where people fell thru the ice and get air in the gap. If there is a gap, how can ice keep getting thicker when it's not touching the water? The ice fishing guys should know if they see a gap when they cut their holes.
This is the first time I've seen my winter diffuser blow a hole that's not directly over the diffuser location. This one is starting just a few feet from shore, about 20 feet from the diffuser. Maybe its water depth? Although the diffuser is in the same spot as last year, the November rains brought the pond level up. The diffuser is in 7 or 8 feet of water this winter instead of 3 or 4 like last year. It's weird!
IMO I don't think you can build up pressure in the pond very "high." Your compressor has limits on the pressure it can output.
Last edited by Bill D.; 01/20/16 05:29 PM.