Freg,

Disclaimer...I am a new owner of a aeration system with only one year under my belt, but have been reading here at PB about the systems for two years now.

With that said, I think running the system before stocking is a good idea. It can't do any real harm and it would let you get used to the system without the worry if a fish kill. I would still bring it up slowly as if you had fish merely to watch the gradual effects and to minimize any lower food chain damage. I would watch the water temps as it comes up and as it continues to operate to get a feel for the effects on the water column temps.

If ample muck already exists, the system would start working on that which would be a benefit even though minor when considering only a few months before stocking, but it would get things stirred up prior to a fish population and allow it to settle out before stocking.

My pond seems to suffer from muddy waters, even more so with the aerator running. I have not figured out the best time schedule just yet to minimize the muddying effects and minimize the hot summer daytime temperature effects. Starting your system early will give you a jump on that learnign curve too.

All in all, I think the benefits would be minimal when considering just the health of the pond (and only a couple months prior to stocking), but well worth doing when you look at understanding the system and establishing a settled pond prior to stocking. One less thing to worry about. Once again, I do not feel that it is too critical to start it early, just a nicer start than I had.

Fish on!,
Noel