It can be reset without tearing it down. Removing algae covered hardscape for cleaning, removal of plants that are too far gone, substrate vacuuming, 50% water changes 2-3 times per week for a few weeks, the addition of purigen or something similar to the filter for removal of organics, filter cleaning, good flow, oxygenation, attention to lighting levels in regards to CO2, etc. will get a tank back into shape. It just takes a bit more patience than the overnight method in this thread.
I agree with this, but in practice often the underlying problem isn't known, and has to be determined through a long process of trial and error. During which the plant mass that has to be discarded because it's too far gone can add up so quickly, you might as well have torn it down.
A couple of personal examples, which I only found by trial and error because they were contrary to common sense and advice:
1) Once for three months I struggled with algae, with everyone consistently saying I should decrease
light, which only made it worse. In the end, it was completely solved by increasing
2) This treatment was originally developed to deal with my oddball staghorn, which is resistant to H2O2 or Excel alone, and grows explosively if you give it too much flow. It was solved in the long-term by reducing flow, and/or redirecting it away from plants, but it took months to figure this out.
So a good chemical reset will always be a valuable tool.