Good article, thanks for posting it.  A word of caution if you decide to use flatworm exit, or levamisole in your tank.  I have done cycles of both treatments successfully installed two different tanks in the past and it has had a negative effect on my echinoderms  (starfish, sea cucumbers, and urchins).   Their flared gills, slow movement, falling over upside down, and general suffering is hard to watch.  All survived but if I ever had to do that series of treatments again I would remove them for the duration.