When treating Ich in this example, one thing always has to be impressed, and that is peoples personal experience of dealing with a certain subject or issue. People do what they feel is right, after reasearching the subject and listening to what others have got to say that worked for them. There is no "you must do it this way, or do it that way", no-one can stipulate that, and they dont. When someone presents a solution to an issue that worked for them, others should either read and accept what the person has said and implement it, or simply take that knowledge and research it and bring yourself to a happy medium with it.
In this situation, nobody is saying "you must keep a tank fallow for a minimum of 8 weeks", what they are saying is that it worked for them. If you do not have your "own personal experience" of a subject, then you have to take on board what people say who do have it rather than cross-examine.
Everyone is here to help eachother out of a sticky situation by passing on their knowledge.
So, if a person disagree's with a way to do something but does not know the solution themselves, then research it and make up your own mind.
Niko