I did read the post given earlier, and this is what I gleaned from it:
"Weaning an obligate piscivore onto dead foods is time consuming and to some extent depends on starving the fish in question. If that fish is newly imported, it might not have eaten a proper meal in weeks, in which case further starving it may weaken the fish, even kill it."
"Some aquarists also believe that live fish offer the best diet for piscivorous fish. This is not necessarily true if only one type of fish is used (see Best Practise below) but in theory at least, a live fish diet should be a reasonable match for what a piscivorous fish eats in the wild. Using a substitute that a species would not encounter in the wild (like brine shrimps or squid) might not provide the full balance of nutrients that it needs."
"The main disadvantage of using live fish as food is the risk of introducing parasites and bacteria into the aquarium. Cheap, mass produced fish, especially goldfish, are maintained in squalid conditions. Mortality, even when these fish are kept as pets, is high. While one goldfish might only pose a small risk to a predator, the risk is cumulative over time. So if you feed a predatory fish a goldfish once every two or three days, even after only a few months the chance of infecting your pet fish with something nasty is virtually a certainty." - I wholeheartedly believe this. That is why I will never feed my big guys anything bought from a local "pet store."
"While some people have also used cichlid fry as feeders, the spiny fins on these fish are problematic for many predators not especially adapted to deal with them. Livebearers, by contrast, are small and soft, and won't choke your prize predator." Is a convict a cichlid? I thought it was, but if it is not, I will look into offering them periodically.
"Goldfish and rosy red minnows can be easy to breed, but they suffer from being high in the chemical thiaminase. They must not be used as the staple diet, because over time they will prevent the predatory fish from having enough vitamin B1, which will cause serious health problems. The muscles, bones, and nerves appear to be most seriously affected." - Can anyone show me photo examples of a predator with these health problems? I'd like to know what to look for in the future, as I've never seen anything like it.
"The other key advantage of raising your own feeder fish is that you can "gut load" them. Predatory animals, even strict carnivores like cats, depend upon the gut contents (usually plant matter) of the prey animals they eat to obtain certain nutrients lacking in meat. This is why cats eat the guts and liver of mice and birds they catch, yet ignore the bits that seem nicer to us, like the wing muscles. Likewise, predatory fish will benefit from being fed feeder fish that have themselves been fed properly. Make sure that the feeder fish have been fed vitamin-ennriched food before they are offered to the predatory fish. Vegetarian and algae-based foods are generally considered the most useful. The feeder fish should be "fattened up" for anything up to a month before being used." This is what I was asking about earlier. Anyone have a better alternative than koi pellets? That's what my goldfish are currently being fed, but I'm open to change that.
"When using feeder fish, only add as many as will be eaten within a few minutes. Ideally, feed just one, and only add another if the predatory fish is still obviously hungry. What you want to avoid is having a bunch of terrified, battered fish swimming about the tank. If nothing else, they will be placing an additional strain on the filter as well as using up oxygen." I agree with this and I practice it. Earlier I said I only feed what can be consumed in 5-8 minutes.
"Use feeder fish of suitable size that they will be killed quickly." Space monkey, yes I agree. The bigger cats eat the larger, 2-3" goldfish, and my bass and datnoid will eat the smaller .5-1" feeders. I catch a good mix of sized each time, so that everyone has an opportunity to catch an appropriate size. My gar has a very tiny mouth, and he would surely starve if I only offered 3" goldfish.
Hope that clears up any questions about my feeding practices.
Space monkey - thanks for the heads up. I think all forums are alike, no matter what the discussion topic. People have different opinions, and people show all sorts of varying research. I think we've had great results with our predator tank thus far, and will continue to post progress in the future. Also, thank you for the additional feeder types to look for.