No one I know personally, over the past ten years or so reading online forums I have constantly heard people say they never do a water change. When asked how long they've had their tank and not done water changes, they tend to say a year or so. When asked if they dose, many said they did. But, the challenge is that water changes replenish many different nutrients, not just the standard ones, and water changes help diminish nutrients and toxins (as we are all aware). I was also able to follow a few and eventually they tended to see die off of critters in their tank, never lasted very long w/success when not doing water changes. If you are that curious I can see if I can track down some of them via the search function, they are on a different forum that I am part of so I will PM you, if I can successfully find any. I'm sure you would like to share notes. Seems there are very few who have been successful for very long w/o water changes.