Sick fish?

I bought a anthias a month and a week ago and had it in qt for 3 weeks. he looked good so i put him in my main tank. Last night i noticed white sugarlike specks on his fins prob ich. He is eating good and acts fine as well as all the other fish. I put traps out last night trying to catch him but all i got was 2 shrimp lol. I may have to try a fishing line and small hook to get him out otherwise he may have to stay in the tank. I dont really want to stress it out that much though. I also dont really want to use a bunch of chemicals. from expierience in the past it seems to make things worse. Im running a steralizer hopeing it may help to kill the waterborn diesease. I realize a steralizer wont work when its on the fish itself. I just hope it doesnt spread.
So what should i do from here?

 

Can i get garlic from the grocery store or do i need to get something like the kent marine brand?

 

Nick it might be stress because i had another one in their but he jumped  out of the tank and died. The one that is left did hide for a few days after but he is out swimming around now. I watched last night and didnt see any other fish bothering him if anything he will ocasionally chase other fish a little.
I really cant take all my fish out and put in qt because i only have a 40 qt and the main tank is a 210. Its weird this fish has anything because the pet store had it for three weeks in qt with copper and i had it in qt for 2 to three weeks. the whole time it looked great.
I picked up some garlic today. Should i lower my salinity will that affect my corals?