Nereus ........... While I have no idea who exactly it was that you spoke with, they were mistaken. There are only two people on this planet that are qualified to speak about the nutritional aspects of NLS, one is the creator of NLS (Pablo Tepoot) and the other is myself. While I do not work for New Life, nor am I paid any monies by them for my contributions, I am an admin/mod on their forum and as I said am only one of two people qualified to answer any questions regarding the TherA formula, or anything else regarding their food. Here's a thread I created on the New Life Q&A forum about the TherA formula several yrs ago.
http://www.newlife.ipbhost.com/forums/index.php?showtopic=256
For a starter, the TherA formula is NOT a medicated food, hence the beauty of it, as their is no risk of pathogens building up some kind of immunity towards it, and becoming super bugs, such as what has happened with many of the old school chemicals & antibiotics used in the past in commercial aquaculture facilities. It is for this exact reason that Pablo began using garlic on his commercial aquaculture facility 20+ yrs ago. (1990) Today many aquaculture facilities have realised their mistake in the overuse & general misuse of medications, and are turning towards natural immunostimulants where there is less risk to the fish, and generally little to no risk of creating super bugs. Pablo Tepoot was simply ahead of his time, and was trying things such as garlic before some of these natural remedies had become mainstream. As a matter of fact, 20+ yrs ago when Pablo began adding garlic to NLS, he was the only tropical fish food manufacturer using garlic in fish food. ALL of the NLS formulas contain garlic, the TherA formula simply contains a mega dose.
Does TherA need to be fed every day to otherwise healthy fish? No. Do I feed the TherA daily - nope. But I know many people who do, some for over a decade now.
The various compounds found in garlic simply act as a parasitic/bacterial
preventative. It will not cure any type internal parasite, or any other form of pathogen that I am aware of. But it will also not lead to any type of super bug, anymore than supplementing a fish with Vitamin C will.
And you're right, it isn't rocket science. Garlic has been used for centuries for its anthelmintic properties, and contains bioactive compounds that thus far have clearly been proven to have a probiotic effect on fish.
HTH