Aquarium advice can come from numerous sources, with almost everyone being an expert in some form or fashion. With all the know-it-alls out there, there is bound to be plenty of conflicting information that isn’t necessarily wrong, but can be quite confusing to a beginner aquarist. So, to find out which info works best for you, pay attention to the source of the material (do they stand to gain financially?) and don’t be afraid to seek input from other sources to confirm what you have been told. In any case, the info shouldn’t necessarily be mistrusted, but definitely approach with caution and make gradual minor changes instead of large or quick ones.