jg74, If at all possible I would put the compressor in the garage, shed or house. It is only a short 25 ft distance to bury an air delivery line to the pond. This will do five things for you. 1. I will insure 100% dry conditions, 2. You will NOT need to build or fabricate a weather shelter, plus pump will have better air circulation for motor cooling. (air circulation & cooling is important for compressors) 3. You will be better able to routinely monitor the operational pressure and periodically (monthly) check on start-up pressurization sequence to see if check valves on diffusers are working okay, 4. garage, shed or house conditions will provide a cleaner air environment for compresssor to operate in, 5. pump will be easier to access than under a deck for checking filters, changing timer, or any other routine maintenence (pump out of sight; out of mind, which makes it easier for neglecting the unit). If you operate pump inside some building, I would not be afraid to warranty the pump for 3-5 years if it was run no more than 10 hr per day during just the open water season.
