Sneakypete, I never claimed to be an expert. Maybe I did not word what I want to say properly, many times I am responding to these at work and do not have the time to go indepth. I have had aquariums with many different types of fish most of my life and have never had a problem. I have never had a bowl or small tank, only medium to large tanks with filters and a substrate.
What I was trying to say previously is that fish should never be introduced to an aquarium newly set up with fresh water out of the tap. Tap water is not good for fish. Hence the reason why I usually let my aquarium run for a while on its own with no fish in it. Also, the temperature needs to be correct before your fish are put in the tank. I do introduce plants before I introduce fish and have never had a problem. I've never had a tank or bowl without a filter. Hence the reason why I said that the water changes must be different with a bowl or small tank. My tanks have only ever had a small water percentage change every week since they had filters running all the time. This was done when I would do my weekly maintenance on the aquarium, i.e. cleaning the substrate and glass.
Thanks for the website though. I'm sure it will prove informative to many people.