PH plays a major role in fish health. I have no idea where this old timer myth stuff came from, but it's certainly just not true. Thing is lots of people read about their fishes preferred PH which is typically based on their natural environment parameters, but the likelihood of the fish being from the wild is very slim, unless specifically listed. It was born, and raised in a aquarium environment, probably just like it's parents. They've been conditioned already in some sense.
I agree with you flight50 on the neutral range statement. In Boston we have amazing water, and a consistent PH out of tap at my house of 7.2-7.4. Luckily for me i dont have to mess with PH. When i breed my geophagus species it takes a frozen food source for a solid week or 2 with some PH buffering to entice them.
I suffer from MTS & have a little bit of everything