With over 7 million home aquariums in the United States, you can easily say that keeping beautiful fish is a popular hobby. One of the reasons why is likely that interacting with fish and aquariums is scientifically proven to reduce anxiety and improve your health and well-being.1
When your fish stops eating, determining why can be challenging depending on the fish you keep, your tank setup, and the filtration system you use. We’ll discuss 10 reasons why your fish isn’t eating and what you can do to resolve the issue.
The 10 Possible Reasons Your Fish Isn’t Eating
1. You’re Giving Your Fish Too Much Food
One of the most common mistakes aquarium owners make is to give their fish too much food. A fish that’s eaten enough isn’t going to eat more, even if you feed it 10 times a day. However, putting too much food in your fish’s tank can foul the water and cause your fish to be overfed and ignore their food.
Aquarists recommend feeding your fish only what they can eat in under 3 minutes. Also, depending on the food, you should scoop out anything left over before it falls to the bottom. Doing this will prevent water quality issues that can cause your fish to stop eating.
2. The Food You’re Feeding Your Fish Isn’t the Right Kind
Although most freshwater fish eat similar foods, saltwater fish often have unique nutritional needs that demand different types of fish you might never have heard of. Feeding the wrong food to your fish is one of the most common mistakes that aquarium owners make, but also one of the easiest to fix.
Depending on the species of fish in your tank, consult a veterinarian or do an additional research of what they eat. If you have common freshwater fish, high-quality, flake fish food should suffice. If you have a saltwater tank, however, you might need several types of food to keep your fish happy and healthy.
3. Your Aquarium Is Overcrowded with Fish
Aquarium experts recommend having an inch of adult fish for every gallon of water in your tank. For example, if you have a 10-gallon tank, you should have a maximum of 10 inches of fish inhabiting it. A 100-gallon tank can have 100 inches of fish or 100 1-inch-long fish.
Overcrowding a fish tank can have several adverse effects on your fish, including stopping them from eating. For example, if you put docile fish with aggressive fish, the docile fish might be bullied at feeding time and stop coming around when you feed them. Also, various species of male fish can become territorial and aggressive as they get bigger. It’s better to have fewer but happier and healthier fish and put species that get along well together in your tank.
4. A Health Issue Is Affecting Your Fish
Several illnesses and fish diseases can affect aquarium fish and cause them to stop eating. If an illness or health issue is the problem, you’ll need to do a few things to solve it. The first is to isolate the ill fish from the main tank and put it in a smaller one until it gets better. Then, you can consult your veterinarian to determine exactly what’s happening and how to help your fish best. Some of the most common fish illnesses include the following:
5. Your Female Fish Is Pregnant
When most species of fish become pregnant, they start eating less a few days before giving birth. Then, a few hours before giving birth, most fish stop eating altogether. You can usually determine if a fish is pregnant simply by looking at her distended belly and noticing that her movements are slower.
If you see that one of your fish is pregnant, gently scoop her out of the main tank and put her into a smaller tank until she gives birth. Within a few hours or, at maximum, a day or two, she should start eating normally again. Then, you can put here back in the main tank again while the fry grow bigger and stronger in the spare tank.
6. Your Aquarium’s Filter Isn’t Doing a Good Job
Most water quality issues occur when the tank’s filter isn’t powerful enough to keep the water clean. One of the problems you’ll see is that your fish stop eating because they’re too busy trying to survive the harsh environment.
What you need to keep in mind is that your fish eat, sleep, communicate, and breathe in your tank’s water, and many species are highly susceptible to even slight changes in the water’s quality. The solution is to purchase a new filter and replace 25% of your tank’s water once a month. So, for example, if you have a 100-gallon tank, you will need to replace 25 gallons of water every 4 weeks. Some of the problems that an inadequate filter can cause include the following:
7. Something Is Stressing Your Fish
The average aquarium fish is an incredibly delicate animal. Many species of fish can be put in saltwater and freshwater aquariums, and some are more durable and aggressive than others. Many things can stress a fish in your aquarium and stop it from eating. Below are a few great examples.
8. Your Fish Need Variety
It’s true that most fish aren’t picky eaters, but some can be. Depending on the species of fish you have in your aquarium, they might be fine with flakes every day, but some might need a little variety from time to time. It’s vital to determine the food your fish likes best and, if they stop eating, figure out something to give them that will entice them again. Your veterinarian can help you develop a meal plan for your fish to keep them healthy.
9. An Electrical Current in Your Aquarium’s Water Is the Cause
Not only can an electrical current in the water cause your fish to stop eating, but it can also be dangerous to their health. The average aquarium has at least two electrical devices to keep it running smoothly. A filter system, heater, bubble maker, and animated tank decorations are some of the most common.
To determine if there’s an electrical current in your tank’s water, you’ll need a multimeter, which is a device that can detect electrical charges. You should also unplug and check any electrical devices used in your aquarium and ensure no wires are exposed. If you have any that appear damaged, replace them right away.
10. The Temperature Is Fluctuating in Your Tank’s Water
Unless your aquarium is exposed to direct sunlight or high airflow, water temperature fluctuation usually isn’t a problem. If it is, the usual culprit is your tank’s water heater. Whatever the cause, temperature spikes in your aquarium’s water can cause your fish to stop eating, sometimes temporarily or sometimes for days.
If, for example, the water in your aquarium is too hot, your fish can become hyperactive and not want to eat. On the other hand, if the water is too cold, it can slow down your fish’s metabolism and cause a loss of appetite. Whatever’s causing the temperature spike needs to be addressed and corrected. That includes purchasing a new water heater if your current one isn’t functioning correctly.
Final Thoughts
There are several reasons why the fish in your aquarium aren’t eating, including overfeeding, overcrowded conditions, and, worst of all, dirty aquarium water. Most problems that cause aquarium fish to stop eating are easy to correct, but some are more difficult.
If you’ve tried changing the filter and some of the other suggestions above, and your fish still isn’t eating, contact your veterinarian. They can tell you what’s happening, what to do about it, and help you save your fish before you find them floating in your tank.
Featured Image Credit: JuanCarlosPalauDiaz, Shutterstock