Many things fall into this class, including many methods people on this board use, including zeovit, which is a point I was making a while back.
Reefkeeping magazine is always worth the time to read, and not just Erics column, Randy's and others are just as useful.
Here's another one which may be appropriate for this forum at the moment.
http://www.reefkeeping.com/issues/2004- ... /index.htm
Layton