Blonde Naso QT HELP

[Reef23]

Hi all,
Picked up a very nice blonde Naso tang today. Before the tang police attack, there is a game plan behind this! He is only 3" and I'm hoping to be able to keep him in my 140G for a year or so. After that I have a friend with a 220G that agreed to take him over once size became an issue. At the store I saw him eat pellets and nori. No signs of any issue what so ever. Once bagged I had a 2hr drive. When I got home he already showed signs of stress with white dots on his sides. I have a 20G QT setup with 1.025 salinity. The store water is 1.024. I'm drip acclimating him now. I plan on hyposalinity treatment over the next 48hrs. Do you recommend a full 4wk QT? My Qt tank is in my "fish room" where my sump is located. I have a light over the fuge that comes on for 8hrs a night and lights up the room a far amount. Is this enough light for the QT or do I need to set something else up? Where do I get garlic to soak his food in ? Any suggestions would be appreciated
Thanks