Garlic isn't necessary to add. From what I have learned garlic doesn't aid the immune system but it does help in other ways. Remember watching old vampire movies as a kid? Garlic was what they used to keep the vampires away. Well there is some truth to the practice. A long time ago we figured out that if you eat a lot of garlic vampire bats stay away from you. This is the same for most blood sucking parasites. If I am going on a campout where the leeched, ticks, or mosquitos are bad, I will eat some garlic before I go. They stay away. Garlic is commonly used in fish medications to help them stay parasite-free. Of course, I could be wrong, it has happened before.