Unfortunately most 'evidence" this hobby has is anecdotal as very little proper research is or has been done. It is so much easier that now the internet has made communication easier and quicker, we don't have to make all the mistakes ourselves and at least we can now benefit from other keepers experience. I prefer to listen to those who have made mistakes and are prepared to share their experience rather than from those who have never had a problem. ... often because they have never had a go.