Why guppy tanks are a great food source for your reef

Besides fatty acids, there are other concerns with various foods. For instance, Cyprinids (members of the carp family...goldfish, rosy reds, etc.) tend to contain high concentrations of the enzyme thiaminase. This enzyme inhibits the pred's thiamine (vitamin B1) uptake, thus making them thiamine deficient. This can result in various central nervous system (CNS) disorders which often present as clamped fins, anorexia (cessation of feeding), seizures, and an eventual early death.

Even certain SW critters when used exclusively/in high amounts can cause issues in preds, such as krill. They are pretty much completely devoid of Vitamins C and B1 (thiamine), and thier shell contains inordinate amounts of fluoride. This often results in mandibular deformation, which can cause "lockjaw" upon striking at food. Additionally, krill contains varying amounts of thiaminase, which is mentioned in the paragraph above.

Since we keep preds, particularly Scorpaenifomes, pretty much exclusively, we've found that generally speaking, once you get a fish weaned and stick-trained, they will more often than not come to the stick rather than a live food item if both are offered concurrently.

Do they NEED live food? Not IMHO. In fact, it's much easier to supplement a fish's diet using non-living fare. I do, however think that most folks overfeed their predators, esp. if they're in a community tank setup, as they will often eat food meant for their tankmates. 4-6 eye-sized pieces of food 3x a week is fine for most preds, as they have slow metabolisms and it takes awhile to digest a meal. As we all know, overfeeding any fish results in hepatic lipidosis (as Vinny mentioned).

All that being said, Renee and I both agree that the weakest link in our hobby is balanced nutrition, and is most likely the "key" to being able to keep many of the "unkeepable" species. If we as a community can "crack that code" for each species, and share the results, it would go a long way to the hobbyist's ability to maintain certain critters in our little boxes of water.

JM .02...