Moving BTA's from 40B to 220G

[TrottingReef]

I have a 220G FOWLR that is currently in fallow period until Jan 2nd due to velvet outbreak. The tank is otherwise 6 months old. I have 6 BTA in my 40B that I have been planning to move to my 220. When should I move the BTA's into the tank, before or after I start moving fish back to the tank?

 

[TrottingReef]

Humble recommended I move them now so will be doing that tomorrow after I replace the heater in the tank. I pulled it to put in one of the 75g QTs I had to set up.