5 Reasons Your Betta Fry Are At The Bottom Of The Tank

Fry refers to newly-hatched fish, so when we refer to betta fry, we’re referring to newly-hatched betta fish. Many betta owners like to breed their male betta fish at some point, leading to a new obligation of caring for the fry. If you notice that some of the betta fries are at the bottom of the tank, this is often a sign that they’re not as healthy as they should be. Keep reading as we explore the most common reasons betta fry end up swimming at the bottom of the tank and how to save them from this sometimes fatal phenomenon. 

Why Is My Betta Fry At The Bottom Of The Tank?

Betta fry often ends up on the floor of their aquariums due to swim bladder disorder caused by poor water or food conditions. We refer to this type of fry as “belly-sliders” since it occurs when the namesake organ mal-develops. This leads to fry struggling to swim, and instead of sliding about the tank’s floor, like bottom-feeders.

Feeding Baby Brine Shrimp to Fry

Baby brine shrimp (BBS) is a common food source for betta fry. However, many betta breeders don’t know that this food commonly leads to underdeveloped swim bladders and swim bladder disorders in betta fry. 

Feeding Micro-Worms to Fry

Although not as common, micro-worms are sometimes associated with swim bladder disorder in betta fry. Coincidentally, betta fries that are fed micro-worms often develop other health issues, too, such as missing ventral fins. 

Not Cleaning the Water Properly

Poor water quality is the other main condition associated with belly-sliding betta fry. Clean tank water is one of the most important maintenance tasks in the early days of a betta’s life. Without it, fry won’t develop properly, leading to them ending up at the bottom of the tank.

Overfeeding Betta Fry

Just as the wrong food can inhibit betta fry development, so can overfeeding them. Overfeeding often occurs when owners don’t reserve a day for fasting, which is essential for proper digestive rest. 

Not Maintaining the Proper Water Temperature

The water temperature in your tank is just as important as its cleanliness. It’s important to keep the aquarium temperature as close to 78 degrees Fahrenheit as possible. You don’t want to let this temperature fluctuate, as it can lead to poor digestion and immune function. 

How Do I Save My Dying Betta Fry?

So, now that you’re aware of the main issues that cause betta hatchlings to flounder at the bottom of the tank, how do you save them? Swim bladder disease itself isn’t usually fatal. However, many overlooked environmental conditions can lead to death in the early days of fry life, which can be avoided.

Improve Water Conditions

Improving water conditions is crucial if you notice your betta fries aren’t doing well. Keep the aquarium water fresh by maintaining a 78-degree Fahrenheit temperature, 0-ppm toxin level, dust- and odor-free environment, 7-7.4 pH, and conditioned water. 

Use Only High Quality Feed

We have already established the problems with micro-worms and BBS. As a healthy alternative, though, you can turn to live and frozen feed with high protein content. Some examples include grindal worms, vinegar eels, infusoria, and walter worms. 

Keep a Strict Feeding Schedule

You should also stick to the same feeding routine of frequent small meals throughout the day. Bettas grow faster and healthier when fed 3-4 times daily in their early days of life. Just make sure to take one day a week (the same day each week) to let them fast and rest their digestive tracts.

Eliminate Aggressive Situations

It’s common knowledge that bettas are prone to aggression when kept in tanks together. Some betta parents will even eat their young to survive. Separate the parents from the fry after one week of life and the males into their own individual tanks around 8 weeks of age. 

Eliminate Parasitic Conditions

This goes hand in hand with our advice about keeping tank water clean. If you don’t regularly clean old food out and change the water, waste will settle at the bottom and grow parasites. 

Is it true that Bettas eat their fry and eggs? Find out the truth here.

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Why Do My Betta Fry Keep Dying?

Betta fry may keep dying despite your efforts due to unsafe tank conditions and other problems. Below are some of the common reasons that they might start to die rapidly within an aquarium. 

Filter Issues

If you don’t have a filter in your tank, the water won’t stay clean and could malnourish your fry and kill them. Or, if you have the wrong kind of filter, the fry might get stuck and die. 

They Are Crowded

Betta can breed a lot of fry at once. It’s easy for a tank to get overcrowded (more than 100 fries per tank). Keep the proportion managed, so there isn’t so much competition for food.

It’s Too Bright

Betta fries need light, but not too much, or else they won’t sleep. Sleep deprivation can lead to exhaustion and even death. 

They Are Killing Each Other

This is common when some fries grow bigger and stronger than their siblings. The biggest fry may kill or eat the smallest ones, especially if there isn’t enough food around.

They’re Diseased

Certain diseases, like betta dropsy, are fatal in betta hatchlings. Dropsy is a common disease among bettas that involves organ dysfunction.


Are Some of My Betta Fry Dead or Feeding Off the Bottom of Tank?

Betta fry at the bottom of the tank may be feeding there due to swim bladder disease that has caused them to not be able to swim. Or, they may have died and settled to the bottom due to disease, poor living conditions, or aggression from tankmates


Betta fries need clean water of the right pH and chemical balance, as well as high-quality food on a strict schedule to survive. When malnourishment and environmental issues arise, betta fry can develop swim bladder disorder or die, sending them to the bottom of the tank.