How do you know the Vitamin C helps you from catching anything? This is the kind of thought I am very interested in....lots of people think things like that, but there often isn't much evidence that the thing people think happens actually happens. Many products are sold, and there are a million in the reefing world that claim to make your fish healthier. Many of these products are sold by getting people to think that it helps keep fish healthier and that 'it can't hurt'. The main point here is that there are lots of people that don't use Vitamin C, or other additives, that have plenty healthy fish, which makes the question - why spend the money on a product that might work, but people who don't use it have the same results as the people that do? Like I said, this is a real interest for me and I realize that it may not be for others so tell me to shut up if I am annoying and I will.