Have power about 500 or so feet away. Heavily forested area, with a path, lots of roots, but I do have a trencher.
Where would I get the kind of black poly pipe you'd use for this?
FWIW I was faced with a similar problem but only about 350 feet from electric. I chose to run electric to the pond instead of an airline. It costs a good bit more to do that for sure, but my thinking was I am probably going to want electric at the pond for other uses in the future anyway so just do the trenching job once.
Edit: FWIW Another option would be to bury the poly air line deeper and if you ever want electric at the pond at a later date, you can pull the wire thru the existing line and move the compressor to the pond.