It can boost immune systems and stimulate appitite...and yes....fresh cloves can be used. I take a slice ...crush it....soak it for a while in a bit of tank water...then use the juice to soak food.
5 to ten minutes? i'd do it while watching tv during one commercial put it in during the next dump it. u just gotta remember all the garlic is going into ur tank water, it's not all going to be in the food itself so be conservative.
i take what ever i plan on freezing..ex. shrimp mussel crab etc garlic..process in processor..stick in ziplock..roll out with rollin pin and freeze break a peice off daily for afternoon feeding...