File completed seeding in Transmission

Trying to figure if this can actually be done, but is there a way to determine if a file has completed seeding in Transmission?

My general logic would include having Hazel monitor the download directory for .part files. Tag them a color when they have gone from .part to .avi as an example. Copy the .avi files of that color tag to another directory and process (convert etc). That would leave the original file in the directory to seed completely. I can see filling a HD quickly this way......

Is there a more efficient way to do this without having to copy large chunks of data (video file etc.)? :idea:

Thanks
jm

I think it's better to use Transmission's preference to have separate folders for downloading and finished torrents. Have Hazel monitor the folder with the finished torrents and it should work as expected.

Thank you Mr. Noodle! I'll play around some more and see what I can come up with.