Hi Vulcanfire,
I don't know if you're still pondering (no pun intended !!) converting your above ground swimming pool to a pond. I just saw your post and thought I'd share that I've done just that!!
Here's a short write-up and some pictures what I did: http://www.kilk.com/pond
I also made a filter myself, tearing out the old pool filter and replacing it with a natural biological gravel filter.
Erik


