Terrific thread, thanks for posting this. Too many keepers, especially of "monster" fish, are situated at opposite extremes of the range of thought regarding feeding their fish. Those at one end of this range think that a tank full of piranhas, peacock bass, arowanas or whatever just needs a couple dozen feeder goldfish tossed in every few days; feeding is often done for a group of buddies fortified with alcohol or other recreational drugs. At the opposite extreme, we have the guys who have read every technical paper ever published about every obscure aspect of fish nutrition, and who make sure that the food they use is absolutely "perfect"...as if every species of fish had the exact same dietary requirements...
Back in my early days in the hobby, it was common practice for Trout Chow to be sold to and used by keepers of big fish, and I was as guilty as most of overusing this high-protein stuff for carnivore, omnivore and herbivore alike. Even then I was aware that it was way too high in protein for many of these fish, and I always made sure to supplement their diets with greens in some form. I also made up my own fish food by combining duckweed, dandelion leaves/flowers, peas, shrimp, bait minnows, mayflies (could easily collect hundreds of pounds of these during the annual hatch back then), earthworms and assorted other goodies in a blender, mixing it with gelatin, allowing it to set and then cutting into cubes and freezing. This ever-changing blend, along with the Trout Chow, formed the basic diet for most of my fish. I supplemented with whole nightcrawlers, mayflies, krill or minnows regularly.
I've got to look into those Gamefish Pellets mentioned above; wasn't aware they existed but they sound promising.
Like others have stated, I think that the variety is key for success when feeding this way. If you are going to feed strictly a prepared diet (I'm not) AND if you believe that our understanding of the nutritional requirements of fish is complete enough that the "best" pellets are nutritionally complete (I don't) AND if you will accept the notion that feeding a single "perfect" food is really the ideal solution (I won't)...then logic dictates that supplement feeding of any "less-than-perfect" food is nutritionally deleterious for the fish. If you have the perfect food, then each mouthful is nutritionally complete. Anything added as a supplement or a treat is, by definition, a negative.
I believe that fish, as living creatures, deserve more than being treated like engines that require only fuel. I try to the best of my ability to provide a stimulating environment, which includes a variety of different foods which, taken as a whole, provide an overall complete diet. Each mouthful of food is not necessarily nutritionally complete...but by the end of the week or the month, the total food intake of the animal constitutes a reasonably complete nutritional package.
Trust me, this isn't motivated by laziness or cheapness on my part. I definitely am both lazy and cheap to a degree, but feeding fish this way takes way more effort than just opening a can or bottle and shaking out some pellets. Assembling all the ingredients isn't free, but admittedly it can usually be done for a relatively low cash expenditure, especially compared to premium-grade prepared foods. You are paying with your time and effort more than with your wallet. For some, expending this effort satisfies our ethical requirements as they relate to the husbandry of aquarium fish; believe it or not, this is one of the parts of the hobby that make it satisfying and fun.
