I didn't use Selcon specifically. We feed a wide variety of foods, use Vitamin C, and garlic routinely. Selcon is HUFA and a lot of the foods we use are also a source of HUFA (Highly Unsaturated Fatty Acids).
Houston is a pig - he eats everything and anything. 2 years of Spirulina flakes he was probably good and ready for some variety.
Jenn