Why Are My Neon Tetras Not Eating? {Are They Sick?}

Are you concerned that your neon tetras are not eating? Are they sick or just eating without you noticing? Let’s find out why these neon tetras are not eating.

Why Are My Neon Tetras Not Eating? Neon tetras can be picky eaters in a new tank or if they’re under stress. They don’t prefer to swim to the surface to eat and could be eating enough from the middle or bottom of the tank. 

Could it be the water conditions? Could it be that they are so small that we don’t notice them eating if they aren’t actively pursuing the food you give them at the surface?

Why Won’t My Neon Tetras Eat At The Surface of the Tank?

You have arrived for feeding time and your fish should be hungry. You notice that your neon tetras are not swimming up to the surface to snatch up the food. There could be some obvious reason for this.

  • Neon tetras are mid-level feeders.
  • Neon tetras are shy or nervous. 
  • They are not used to the tank yet. 
  • They are scared of aggressive neighbors. 
  • They are not hungry. 
  • They aren’t interested in that particular food.

Neon Tetras Are Mid-Level Feeders.

Neon tetras are rather small and they have the right to be nervous in the wild. If they were feeding at the surface of natural waters, they would be an easy catch for birds to prey on.

Neon tetras can and will get comfortable in your tank. Once this happens, they will swim to the top of the tank as well. Mid-level feeding is common for many neon tetras. The food may moisten up once it starts to drop and it becomes easier for them to fit it into their small mouths.

Neon Tetras Are Shy or Nervous.

It’s very common for neon tetras to hide in your tank. They will be behind or in your plants, decorations or under rocks. They tend to be more shy when they are in smaller groups or alone.

Due to their small size, they might need some time and assurance that the tank is safe for them to come out of hiding to eat.

They Are Not Used To The Tank Yet.

It a rather shocking experience to be taken from the wild and transferred to a local fish store. They may also be bred in captivity and transferred over to your tank. The movement stresses them out.

This type of stress is caused by moving into a new tank and they’ll need some time to adjust to it. It may take a few days to a few weeks. They may not be eating at the surface, but there are scraps at the bottom of the tank small enough to fit their little mouths.

They Are Scared of Aggressive Neighbors.

Some fish will prey on neon tetras. During feeding time, if there are other tankmates swimming around and eager for a meal, the neon tetras may become the meal.

Neon tetras are apprehensive about this and may hesitate to swim out and eagerly eat what you’re giving them. Since they don’t need much food to survive, they’ll go looking for leftovers after the bigger fish are done.

They Are Not Hungry.

It could be that you are giving them too much food. Sometimes we get used to feeding a certain amount of food to our fish and disregard the various amounts for each specific fish.

The neon tetras may not be hungry at the time you are feeding them. Consider changing up the schedule or the food.

They Aren’t Interested In that Particular Food.

It’s important to vary the food for the neon tetras. They have small mouths, but they still enjoy small pieces of brine shrimp or bloodworms. They have to be cut up very tiny. Pellets are not natural to a neon tetra and will take some time to adjust to them.

What Is The Best Feeding Schedule For Neon Tetras?

It will be up to you to fit feeding times into your schedule. Neon Tetras are pickier eaters than many other fish, but they don’t require special times outside of your regular schedule.

Follow the same times as you would for your other fish and try to stick to once a day. You can feed them twice a day as well, but expect them to not eat as much. Grind up pellets or flakes in your fingers and make sure they are small enough for the neon tetras to fit them in their mouths.

How Long Can Neon Tetras Go Without Eating?

Neon tetras are omnivores. They can survive on plant matter if there is insufficient food for them to eat elsewhere. A neon tetra can easily go 3 days without food.

An adult neon tetra can possibly last 2-4 weeks without food if there are live plants in the tank. They may be able to feed off plant matter that floats around the tank, but this is not ideal.

Consider the negative effects of going this long without feeding the neon tetras. They may survive in their weakened state, but they could be stressed and lose color or get sick.

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What Can I Do To Encourage A Neon Fish To Eat?

There are few options to consider. Let’s look into them.

  • Vary their diet.
  • Introduce live food.
  • Cut up or grind the food smaller.
  • Use micro-pellets.
  • Try algae wafers.
  • Feed them insect larvae.
  • Starve them a little.

Vary Their Diet.

Fish don’t like to eat the same thing daily. If you add some tasty snacks or a variety of meaty food, it might waken their appetites. Some of the foods below should liven them up.

Introduce Live Food.

Neon tetras will certainly eat live food in the wild. We can start by adding bloodworms that are tiny enough to fit into their mouths. If the bloodworms or shrimp are live, they may need to be cut down to a smaller size before attempting to feed them to your neon tetras.

Cut Up or Grind the Food Smaller.

Some neon tetras attempt to eat the food your are giving them and then decide to spit it out. They may feel like it’s too much work to get the food to slide down to their bellies and they’ll look for something smaller.

Try breaking up the food in any way you like to make it much easier for them to eat it. Look closely at the size of their mouths and go from there.

Use Micro-Pellets.

This type of food isn’t available in the wild. It could take time for them to adjust to it. Regular sized pellets could be too large for your neon tetras. Micro-pellets should do the trick if they are balanced and introduced alongside tastier food like brine shrimp.

Try Algae Wafers.

Look around for these things. Some experienced neon tetra keepers say that their fish go crazy for them. It’s worth a try if you can order them online or find them in your local fish store. Lets us know how it goes!

Feed Them Insect Larvae.

Feeding your neon tetras insect larvae helps mimic what they eat in the wild. You can buy them frozen as well. Make sure to thaw them out first. They should enjoy the tiny larvae and it will help revive their appetites.

Starve Them A Little.

A little means a day. See if a one day fast helps to pick up their hunger. Fasting also helps to clear their bellies and reduce bloating or digestion problems. You can starve them a little longer, but try not to exceed a couple days.


If your neon tetras are actually maintaining their beautiful colors, they are most likely eating enough. They may not swim to the surface, but they are finding enough moistened or smaller bits of food to keep them going. Vary their diet to see if it picks up their appetite.

Neon tetras are fun to enjoy. We hope the experience improves for you and you feel the same way!

Brian Arial

Brian Arial has kept fish for leisure and worked with fish stores for most of his life. He enjoys writing and caring for aquariums and ponds.