Have recently read an article in this months edition of CORAL that really dispells some of the "myth" behind water changes. I do them mainly as a way to manage minor elements in the tank and run a massive skimmer to get rid of the waste. I do change 40% over the course of a month but that 40% is over time. I change 10% a week on a 350 gallon system. I am not really affecting organics all that much with the water changes (still does not mean they should not be done) and this is one reason why we can change water all day and still not get nitrates down to far without more negatives than positives in our tanks.

I do believe the real benefits are the minor elements that are replenished and the little boost we get in the major elelments when a good salt is used and that is why I keep doing them.