Availability of Foods for Saltwater Fish
Commercial fish foods can consist either of a single ingredient, such as freeze-dried brine shrimp, or a compound of many ingredients, such as most flake foods. The trick to providing a balanced diet for your aquarium is to feed a wide variety of foods, alternating among two or three kinds during the course of a week. If your fish are primarily vegetarian, you will find products made just for them. Supplement these with small amounts of animal protein, frozen brine shrimp, for example. Conversely, if your fish are primarily carnivorous, supplement their diet with small amounts of vegetable matter, such as products containing saltwater algae.
Fish food may be supplied as flakes or as pellets, in freeze-dried form or frozen. Many dealers also stock live foods.
Feeding Marine Fish
Beginning aquarists usually give too much food. This results in an excessive load on the filtration system, since uneaten food simply decays on the bottom of the tank. The notion that fish will eat themselves to death is nonsense, but the pollution in an overfed aquarium can certainly wipe out its inhabitants.
A fish’s stomach approximates the size of its eye. Obviously, it will not take a lot of food to fill it up. One rule of thumb is to feed only as much as will be consumed in ten minutes. You can determine the correct amount for your situation by trial and error. When in doubt, feed less. Fish can go for a surprisingly long time, weeks in many cases, without eating, so the likelihood of starving them is quite small in comparison to the likelihood of polluting the tank with uneaten food.
Most people find twice daily feedings work best with their schedule. If your schedule permits, though, feed a community of smaller fish about five times daily with just a tiny pinch of food at each feeding. Feed about an hour after the lights come on in the morning, and again about an hour before darkness falls. You will need to modify this schedule if you have, for example, large predators like groupers and lion fish. For these, the usual feeding regimen is three or four times a week. On the other hand, vegetarians feed almost continuously. These fish do best when there is plenty of algae growing in the tank to supplement the twice daily feedings.
Be careful not to feed vegetarian fish a diet rich in animal protein, even though they may eat such food greedily. The vegetarian digestive system is not designed to cope with such a diet, and problems will develop. Similarly, fish that need plenty of animal protein will not get enough to eat if kept on a diet better suited to vegetarians.
In the natural environment, of course, diets consist mostly of living foods. Some live foods can be cultured at home, provided you have the time and inclination. Ideally, one would feed only live food, but this is usually impractical at home.
Live Foods from the Aquarium Store for Saltwater Fish
Virtually all aquarium dealers stock feeder goldfish. They are sold by the dozen and keep well for a week or so in a small, aerated container. Ten gallons of water accommodates about one dozen. Instead of a glass tank, you can use a plastic trash can outfitted with an airstone. Goldfish do fine in cold water and can be kept outside year round, as long as the water does not freeze. If you only purchase, let’s say, a dozen a week, change the water between batches of goldfish. Unfortunately, only large, predatory tropical fish will consume them, so feeder goldfish are not for every aquarist.
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