By pre-boiling, do you mean the whole 5 gallons before adding the salts? I filtered the entire 5 gallons, then boiled about 1 gallon and added the salts to this.
I have just moved it to the secondary fermenter (first time I have used a secondary

) but it looks and smells great!
On the use of a secondary fermenter, I have a small question.... why use a secondary?

Before now, I have always transferred from the primary to a pressure barrel or bottles.