How often should I feed fish? How much should I feed fish? These are common questions from novice fish hobbyists. Feeding fish can be fun, and it is an essential part of keeping an aquarium. Many people think it is easy and there is nothing to it they need to learn. It is a false assumption. One of the top reasons for many fish dying in home aquariums is overfeeding. Overfeeding can cause severe problems including but not limited to polluting the water in the fish tank, stress the fish, or even directly kill the fish when their digestive systems couldn’t handle it.

How often should I feed fish?

Although it is recommended to feed the fish only once a day, it is not the only way to keep fish healthy. Some people feed their fish every other day, and others feed fish twice a day in smaller portions.

In a natural environment, fish don’t usually eat big meals. They are opportunists who will eat when there is food available. Some fish species in the wild will forge all day for one tiny bite at a time. Sometimes they might not get any food at all for days. While it is unnatural for them to have big meals, it wouldn’t hurt them if big meals don’t come too often. That is why the once-a-day feeding routine is excellent for most fish keepers.

If you decide to feed fish twice a day, please do not double the amount of the food. Instead, you should just divide that one meal into two smaller meals. For those who decide to feed their fish once every other day, just supply as much as you would have fed them once a day. Do not increase the quantity of each meal just because you do not feed them daily. Do not increase the amount of food in one feeding just because you have skipped one.

How much should I feed fish?

There is no exact set amount for how much you should feed your fish. The typical recommendation is to feed as much as the fish can finish within 10 to 30 seconds if you only have one fish. It can mean only 3~5 pellets or a few small pieces of flakes for one fish. As for the pellet size, it is best to be as big as the fish can swallow the whole piece.

If you have a full tank of fish, feed only as much as they can finish within a minute. Usually, just a small pitch or two is enough for many fish. As long as every fish is getting a few pellets (even only 1 or 2), there is no need to feed more. No leftover food should be visible at the end of the feeding. If you see uneaten food being ignored by the fish, you are overfeeding and must decrease the amount the next time.

Remove leftover fish food immediately after feeding
With the exception of the sinking food (such as algae wafer) for bottom feeders, you should always remove any leftover food you see in the fish tank immediately after feeding by using a fishnet and aquarium vacuum. It is crucial to avoid polluting the aquarium water. Rotting fish food can cause an ammonia spike and set the aquarium nitrogen cycle off balance.

It is said that most fish species have the stomach the size of their eyes. Although their stomachs are capable of expanding to hold more food, it is unhealthy for them to overeat each meal. Too much food in the stomach can cause digestive problems, and in severe cases can cause fish death as a result of being unable to digest the food they ate. This is more likely to happen when you feed pellets because pellets can expand in the fish’s stomach after absorbing water. If your fish have too full bellies after the feeding, you might also need to decrease the feeding quantity.

Should I feed fish more food if they still look hungry?

No. Fish might look hungry, and they are still begging for food. Many of them do not know when to quit until it is too late.  Because in the wild they are not used to getting dry food like pellets, or more food than they can handle. It is up to you to make sure they get just the right amount of food.

When feeding fish, the less food, the better.
If you are not sure what exact amount is the right amount, just feed less instead of more. Fish are cold-blood animals. They do not use a lot of energy to maintain a body temperature like us humans. It means they do not need to eat a lot at all and they will not easily starve to death. Feed them less food than they should cause little concern. Overfeeding is the killer. Therefore, you should instead feed less than more.

Things to avoid when feeding fish
Do not dump fish food directly from the bottle into the fish tank. Use your fingers!
Do not hold the fish food bottle directly above the fish tank during the feeding. There is always the risk of accidentally dropping too much food or even the whole bottle into the fish tank.

I am not going to be home for a few days. Will my fish starve?

As we have discussed, fish are cold-blood animals. They do not require a lot of energy to stay alive. They can easily live three weeks without food. No need to cause any concern if you are only going to leave for a few days or a week or two. Do not try to feed them more than the usual amount before your departure, because it might cause more harm than good if the water quality goes south while you are away.

If you have to be out of the town for longer than 2~3 weeks, you should arrange someone to feed fish for you. The biggest problem with having someone else to feed your fish for you is that someone might overfeed and cause more harm than good. Therefore, it is recommended for you to divide the fish food into prepared portions for the temporary fish caretaker. The caretaker does not even need to come in every day. Once or twice a week is totally fine.

An automatic fish feeder is another option if nobody will be able to feed your fish for a long period. It is highly recommended to test the automatic feeder for at least a few days before you leave. Some of them might be malfunctioning which might cause overfeeding or no feeding at all.