I do a nutrient additive to my frozen, I think the fish have really liked it (except for my fish that prefer nori and peas). I would think flakes are more universal, so some of those go in here and there. The first time I went to a LFS, the owner told me that putting fish (like Lions, for example) on frozen makes them more tank-appropriate. The thought that if they aren't used to catching fish, then they aren't as likely to.. now if its rational or not? I don't think my clown is going to start chasing around the other fish, if I was feeding it live brine. There are some fish I would feed a live fish to (I have fed a molly to a shorse), as to the recommendations of experts. I do everything on a schedule & as appropriate for the tank. I don't feed my dog variety, I think his stomach prefers to have something consistant, so go figure.