These past few days I decided to look into what contemporary wisdom advices on feeding fish, and the general contentious is that commercial flake and pellet foods are enough, arguing that these foods are specifically formulated to fulfill your aquatic buddies all the nutrients they need.
Although that seems sound initially, one has to remember that in the wild fish do not get the same types of nutrition at the same exacting quantities that it may get in captivity. Also, most commercial fish food in the market today contains ingredients that fish will never come across in the wild, such as corn and wheat.
A more varied natural diet, composed of non-processed matter is probably closer to the nutrition your fish would have in the wild - the same nutrition that it probably consumed as it evolved from a more primitive fish to the beauty it is now.
But the problem is, even if we know exactly what our particular fish species eat in nature; at what quantities and frequency, attaining these natural fish food may be costly if not impossible in a daily basis.
And here is where commercial fish food comes into play. It takes a lot of guess work out and gives the hobbyist something cheap to feed their fish.
But is feeding your fish commercial food day in and day out really the best path in feeding your fish? Is it even healthy in the long run? No one really has the definitive answer hence the countless debate that has raged on in the fish keeping community for decades.
What I do know is that so called staple "fish food" can be boring not only to the fish fancier but potentially also to fish. Another thing I know is that my experience has thought me that commercial fish food is not the only way to go.
In fact I when I was a child, my uncle Willy, who had already been keeping fish long before commercial fish food was widely available as it is now, recommends feeding krill to carnivorous fish such as cichlids.
Whenever our family visit my uncle Willy, he would entertain my parents with small talks and chitchat while his large aquarium would entertain me for hours. I distinctly remember staring in wonder at impossibly large and healthy fish for hours. Those fish where primarily fed with natural foods such as krill.
Sun dried krill is a widely available food ingredient in many Asian countries and is known natively as "alamang". My uncle advised feeding dried krill as part of my fish's regular diet because it is widely available, costs a fraction of what commercial fish food costs, and more nutritious than commercial foods.
Him having a lot of experience in aquaculture; raising and growing Tilapia, and by seeing his own aquarium fish, it is easy to take his advice.
And the wisdom of the advice is still sound even today. Krill is basically composed of the highest quality protein and calcium, the two most important nutrient a fish would need. Protein builds up the fish's body and calcium its bones, teeth, gill covers and scales.
Today, I feed my cichlids sun dried krill at least four times a week, and the rest of the days I feed them commercial fish food, and home made fish food for variety. Juvenile fish still yet to attain their full size will specially benefit in this routine.
An additional bonus in feeding your pets krill is that is its very rich in carotenoids, which will naturally bring out the color of your fish.
While krill is a great staple for primarily carnivorous fish such as your cichlids, some catfishes and the like, fish that require more green matter, such as gouramis and carps (goldfish/so called freshwater "sharks" etc), would benefit from krill as a supplementary diet as it contains high quality protein and a large quantity of calcium any fish would need.
Krill is also a natural food, and is intended by nature to be a source for many aquatic animals. Some animals such as certain whales live primarily on these.
A pack of sun-dried krill for human consumption
If you are going to buy krill, I would suggest buying the sun-dried variety from the grocery store instead of buying krill from a fish shop for two reasons: the first one being that 1) It will be much cheaper than buying from a pet shop and the second one is that 2) it would be food grade - generally, food grade(fit for human consumption) have less preservatives (sometimes hundred times less) and more hygienically processed (and will less chemicals involved) than even the most expensive products intended for animal consumption.