Finding the Right Flake Food for Aquariums

Confusing, but Important to Get Right

feeding swarm buenos aires tetra aquarium fish eating flake food
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Flake foods aren't what a fish would eat in nature. However, dry flake foods do provide the nutrients fish would find in a natural diet, along with supplements to ensure good health. Here’s what you should consider when choosing flake foods for your fish.

A Hungry Fish Is a Healthy Fish

It is best when feeding your fish, to do it in small amounts, not more food than all your fish can completely eat in about five minutes. Do not make the mistake of overfeeding when you are feeding your fish, allowing flakes to remain on the bottom! Fish will rarely eat left over flake food on the bottom of the aquarium, and scavengers would have eaten it if they were still hungry. 

Until you get a feel for how much flake food your fish will eat, you may over-feed the aquarium. This is a problem, unless you take quick action. You must either net the excess food out of the aquarium, or siphon it completely off the bottom and out of the tank.

A new fish keeper is faced with a wide variety of foods in the average tropical fish retail establishment. On average, you will find 10 to 20 formulas and brands of flake foods, another dozen or so granular foods, a variety of pellet foods and a freezer full of frozen foods, all marketed for feeding your fish.

It can be very confusing, but just remember most aquarium fish are omnivorous. These fish eat food of animal protein origin as well as plant origin.

Look For Protein Source and Content

Protein is the essential nutrient in the fish diet. However, like all good things; too much, too little, or the wrong type of protein can cause problems. The best protein comes from, you guessed it, other fish. The ingredients are listed in order of the greatest quantity first. Select a food that has the first few ingredients listed as fish meal, shrimp, and other seafood on the label. Fish don't need much carbohydrate in the diet, so avoid foods with a large number of grains, or grains listed as the first ingredients.

Food for young fish should have 35 to 45 percent protein. For older fish, less protein is better. Too much protein for mature fish can make them fat and causes fatty liver disease (hepatic lipidosis). Look at the Guaranteed Analysis on the food label to see what the protein content is in the food.

Keep it Fresh

Nutrients in flake food deteriorate over time; in fact they deteriorate rather quickly. It's best to only buy what you can use in one month or less. Select a variety of foods, and rotate for each feeding. This gives you a higher chance of supplying the proper nutrients, while introducing variety into the diet. Using freeze dried, frozen or pelleted food along with the flake food provides great nutrition for all types of fish.

Some manufacturers package several types of flakes in a single can. All you have to do is twist the top to get a different selection. It's a great way to offer your fish variety without purchasing multiple cans of flakes. I highly recommend trying one of them.

Not Just for Vegetarians

Some fish only eat vegetable matter. For them it's critical that you provide foods such as Spirulina (algae) flakes. However, you'll find almost all your fish will enjoy a serving of algae. Flakes are ideal for top or mid level feeding fish, while algae wafers and sinking pellets work best for bottom feeders such as plecos. Take care when feeding algae wafers; feed only one at a time and observe how long it takes your fish to eat them. If the wafer hasn't been consumed within 24 hours, remove the remainder so it doesn't foul the tank. If it is consumed quickly, it's safe to feed more than one disc at a time. Also, be aware that some catfish or other bottom feeders are nocturnal, so they will come out to eat after the lights are off. Feed those fish right before turning off the aquarium lights for the night.

Pellets and Sticks

The larger the fish the larger its appetite—and its mouth. Naturally, large fish prefer something larger to eat. Floating and sinking pellets or sticks are a good choice for larger fish such as cichlids. You will find them in various sizes, designed to match the size of the fish. Become familiar with what your fish eat in nature. Some large fish, such as the Silver Dollar, are vegetarians even though they look like meat lovers. Be sure to offer them some vegetable pellets.

Other Foods

In addition to flakes and pellets, there are also freeze-dried foods such as krill, tubifex, and shrimp. Tubifex generally comes in cubes, which can be firmly pressed to the inside glass of the tank. This gives smaller fish a chance to compete with the larger fish for the food. You'll enjoy seeing them tear into it - they almost look like a pack of wolves. Another great option is frozen food cubes. Frozen foods are made from a variety of ingredients, such as brine shrimp, worms, vegetables and algae. These are very nutritious - and the fish find them delicious.


When introducing new foods, watch closely to see if it's eaten. Any uneaten food should be removed from the aquarium, or it might foul the water.

Feed your fish a varied diet consisting of a flake food as the main ingredient, as well as a occasional meal of freeze-dried, frozen, or pelleted foods and you can't go wrong. Your fish will be healthy, colorful and will grow robustly.

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  1. Nutritional Diseases of Fish. Merck Veterinary Manual.

  2. Aquarium Care and Maintenance: Nutrition and Feeding. Florida Department of Agriculture and Consumer Services.