
The old Jain (India) proverb about the 6 blind men and an elephant comes to mind. (
http://www.jainworld.com/literature/story25.htm) Back in the mid '90s I did a simple experiment setting up six 15 gallon tanks the same and after 6 - 7 months I had 6 different tanks. (Isn't one of the definitions of insanity to do the exact same thing over but expect different results?

) While my experiences are in line with Billsreef and your own I have learned the biology in our tanks is in a constant state of change and I do not do a big water change lightly. Even though I do things the same week in and week out, year in and year out, I do not expect my tanks to stay the same. If I do not expect my tanks to remain the same with consistent maintenance why should I never expect problems to occur with large water changes?