I got this from a sight that sells supplements:
"Selcon: an aquarium food booster that features highly unsaturated OMEGA 3 fatty acids, Marine Lipids (200 mg/g), Stabilized Vitamin C (200 mg) and Vitamin B12 Cyanocobalamin (240 mcg). Soak any freeze-dried, frozen food or dried food to give it additional nutritional value or use directly in the tank to benefit filter-feeding invertebrates. American Marine Selcon does not alter water chemistry and it does not contain Yeast, Phosphates or Nitrates. It also helps cure Head and Lateral Line Erosion / Disease. 60mL. "
And Zoecon:
"Kent Zoecon is a properly preserved food enrichment product designed to provide freshwater and saltwater fishes with essential marine lipids and the omega-3 fatty acids EPA and DHA. Zoecon will benefit fishes that have a diet deficient in lipids, and in which signs of head and lateral line erosion are present (pitting of the skin in the facial region and lateral line). Using Zoecon as a food soak and fortifier of live foods increases the portion of lipids and highly unsaturated fatty acids (HUFA’s) in the fish’s diet. Also, the addition of deepwater shark liver oil containing alcoxyglycerols enhances fishes’ immune systems, and is useful in treating fish with injuries caused by rough handling and fighting with other aquarium inhabitants. Regular use of Zoecon can help prevent nutritional imbalances in fishes and invertebrates (both passive filter-feeders and active foragers). When used in conjunction with Kent Zoe Freshwater or Zoe Marine, fishes and invertebrates are provided with sources of marine lipids, omega-3 fatty acids, bio-available vitamins, and minerals."
So, it sounds like they are both pretty similar in function. I use both, in addition to Zoe and occasionally Garlic Extreme, although I don't use the garlic very much. Since I have started using vitamins I have noticed a huge difference in the health of my fish. For a while I was battling small outbreaks of ich in my tank and my Cortez Angel used to get strange spots on his skin that looked like hole-in-the-head disease but wasn't. (the patches would dissapear the next day. I never did find out what it was) I started using supplements and, boom, the problems went away. I figure that I'm not hurting anything by using both brands.
