What A Guy Won't Do For Some Ducks!

Depending on how old the 1.5 cfm rotary pump is it may or may not be noisy. About 5-7yrs ago GAST added a quiet running "head" on many of their rotary pumps. Your pump will have 1/4" NPT threaded inlet and outlet ports.

All GAST pressure relief valves assoc. w/ rotary pumps that I know about are adjustable. Most have 3/8" NPT thread fitting. My check valve comes with a pipe adaptor for 1/2" blk poly pipe. I use it exclusively on our GAST rotary vane pumps. 10 psi is pretty standard max presure for most all rotary compressors. Special models go to 15psi.

Twice the air flow should give you twice as many bubbles and maybe? twice a larger open hole in the ice. That is assuming the 'diffuser' is the same for each.

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