Not to take this off track, but I think this is an important "principal".
I think any new aquarist should really pay attention to this. If you've been neglecting your maintenance for a long time and things are out of hand don't go in and do a huge water change while simultaneously cleaning out all your filters in the hope of getting back on track. Start with smaller more frequent water changes and go from there. Stability is going to be key. Don't shock the system, gently get it back on track and then you can move towards larger water changes once a week or as dictated by your tank's individual needs.
