Fish Food Nutrition

How to read a fish food label

The guaranteed analysis, the ingredient list and the moisture figure tell you more than the front of the package. Read those three first. Then check pellet size and storage advice.

The guaranteed analysis

You will see minimum crude protein, minimum crude fat, maximum crude fiber and maximum moisture. Carnivores such as bettas usually do well on higher protein. Plant eaters such as many plecos need more fiber and vegetable matter. Energy is rarely printed, so the kcal column above is an estimate for the category.

Ingredient order

Ingredients appear by weight before processing. Fresh fish lists high because it holds a lot of water, and it weighs much less after drying. Fish meal lists lower and can supply more protein. Watch for one grain split into several names, such as wheat flour and wheat middlings. Together they may outweigh the first ingredient. Whole fish and shrimp meal digest well for carnivores. Plant ingredients suit plecos and many cichlids.

Common ingredients

Fish meal and krill meal supply animal protein. Spirulina and algae supply plant matter and pigments. Wheat flour and wheat germ supply carbohydrates, and wheat germ digests well in cool water. Soy products supply protein at lower cost. Astaxanthin supports red and orange color in some foods.

Red flags and marketing claims

Be wary of labels with no analysis, no date or vague wording that hides the ingredients. Words such as "natural" and "premium" have no fixed meaning on fish food labels. A clear label does not guarantee a good food, but a vague one gives you nothing to judge.

Moisture changes the picture

A food with 90 percent water looks weak on paper. Flakes and pellets hold about 6 to 8 percent moisture. Frozen foods hold 85 to 90 percent. So a gram of frozen food carries far less energy than a gram of pellets.

Compare moist foods on a dry-matter basis in the fish food comparison tool. Then use the fish feeding calculator to turn calories into grams of the food you chose.

Flake, pellet and frozen food

Flakes are light and cheap, and they suit small surface and mid-water feeders. They break apart fast, and overfeeding them clouds the tank. Pellets are denser and pack more energy per gram. They come floating or sinking and in several sizes. Soaking helps fish that gulp air. Gel and frozen foods add variety. Thaw frozen food first and keep the thaw water out of the tank. Most keepers use them as part of the diet and not all of it.

Freeze-dried cubes swell once they get wet, so soak them before feeding. Live foods can pull a picky fish into eating, but they can also carry parasites. Many keepers use frozen foods instead.

Match the food to where your fish feed

Surface feeders such as bettas, gouramis and guppies take floating flakes and pellets. Mid-water fish such as tetras and angelfish take slow-sinking food. Bottom feeders such as plecos need sinking wafers or pellets. Match the food to the level, or the wrong fish will eat it. Pick a pellet size that fits the mouth.

Switching and rotating foods

Mix a little new food into the old food over about a week. Feed a staple flake or pellet on most days. Offer a frozen food once or twice a week. Add a vegetable or a gel food for plant eaters. A treat day still counts toward the daily total, so replace part of the meal and do not add on top.