I refer to much of the so called "common wisdom" in fish keeping to be Urban Aquarium Myths. I would say the despite rewriting the fishless cyling article here and especially the two on rescuing a fish in cycle gone wild, that some of these myths are being repeated, but at least less often than 12 year ago when the were many articles on failed cycles.
One of these is that one must do a big water change if ammonia is present at any level and the same for nitrite. While it is mostly true for ammonia, it is far from being a universal. But, most folks have no idea of how to determine if they should not do anything because of a low level ammonia reading. Even worse is one never needs to do a water change for nitrite unless you do not have access to salt.
The entire sw side of the hobby know their fish are almost never at risk from nitrite because they live in salt water and the needed chloride which block the nitrite from entering a fish is always present.
his is just one more example of why some keepers will never get it right. Most of us learn really early that we should not keep big fish in smal spaces. The people who think a fish only grow to the size of the tank do not keep their large growing dogs in a closet to keep them smaller. Or at least most would not.
Over the years I have spent at least $40,000 buying fish. Fortunately by their spawning in my tanks I was able to recoup those costs. Along the way I have learned a great deal about how to care for the fish I keep. With the exception of a few egregious mistakes which killed fish, my fish have pretty much lived a long time. But, I knew from day one that when I put fish into a glass box, they became my total responsibility. How long they lived, how well they did, how healthy they would be was pretty much up to me. And I very early realized that I should not keep anything for which I could not care for properly. This meant parameters, tanks size, diet and which cohabitants were OK. Plus if they got sick, I had to be the doctor to the best of my abilities.
While I am far from perfect in all of this, I can at least know that I do my best to give all of my tank buddies the best life I possibly can. All I can say it that today, going into year 25 with fish is that I still do the happy fish dance every time I see new eggs or fry in my tanks. I am not as spry as the first time I did it, but I still can do a few steps
