No matter how much one tries to dodge it, it can't be ignored that a consistent water change schedule is the most obvious commonality shared by successful reef tanks. It doesn't take long to realize the most experienced reefers push this as the staple of success. Not only are they helpful in removing waste and nutrients, they are even more valuable by replacing elements coral rely on to thrive.
I find the schedule just as important as the water change itself. Diligence in changing a consistent volume with a reliable timeframe ensures stability. Stability, in my mind, is the number one absolute in keeping coral. Water changes are the simplest and easiest way to keep tank parameters stable. Why would one want to dose a bottle of this and that to try and keep parameters dialed in? There are many elements that go untested which can be easily stabilized by a routine water change schedule. The deficit of such might take time to show itself, but it will.
I liken water changes to changing the oil in an engine. If you stop doing them the car will continue to run. No one would argue that the instant you go past the recommended mileage the car will break down. In fact, it might continue for many thousands of miles. But how long down the road before things goes terribly wrong?
There are many methods and practices out there in hopes of removing organics and waste within a reef aquarium. Many of which do a very good job. Skimmers, algae, live rock, etc. But no matter how well these items perform, they will never be able to keep up in removing the amount of organics we introduce into the tank by feeding our fish. Skimmers will never remove enough organics on their own. Algae cannot remove particulates before they begin to break down. And the life within our rock and sand can only go so far in consuming these organics. These dissolved organics have to go somewhere, they are never processed to the point of complete elimination.
Yes, there are exceptions. You can employ different tasks like siphoning your waste into a filter sock and dosing different items into the tank, but I can't help but ask myself why complicate something that can be so very basic, simple and beneficial as a water change?
The only reasons I can think of are time and money. Unfortunately I can't ever imagine a reef aquarium that is set and forget. If this is a goal, I expect there might be some struggles. Even the tasks we automate in order to simplify the work involved require weekly or monthly prep or intervention. Nothing will take care of itself indefinitely.
As far as cost, salt is very cheap in the grand scheme of things. I've always thought it a wise decision to pay $45 for a box of salt in order to keep the many hundreds, if not thousands of dollars of fish and coral healthy within a reef tank. These are living things and it is only wise to act responsibly when entrusted with their care.
For every tank that is successful without performing water changes, I would wager that there are easily many more with proven success by utilizing them.
