Are Guppies Top Water Swimmers?

Guppies are naturally top-level swimmers and will swim near the top of the tank. If your guppies are exhibiting abnormal or concerning behaviors like gasping at the surface or swimming abnormally, there’s probably an issue with the composition of your tank. 

In the following sections, we will spell out the healthy swimming habits of guppies and describe how to discern normal behavior from signs of a possible problem.

Are Guppies Top Water Swimmers?

According to the experts at Interpret, guppies by nature swim towards the top of the tank. You will notice that other types of fish are attracted to the middle and lower areas. They should venture out to explore other spaces too, but they will primarily return to their area of choice.

If your guppy appears healthy and happy, there is no need to worry about its preference for the top of the tank. If this behavior is paired with odd actions like gasping for air, swimming upside down or vertically, floating, or fading colors, it is time to do some digging and determine what needs to be changed in your tank.

Guppies in freshwater aquarium

Why do Guppies Swim at the Top of the Tank?

Not only are guppies top level swimmers, they also prefer the top of the tank because oxygen is more accessible there. If your guppies are not leaving the top of the tank or appear to be floating on the surface, there might be an oxygen deficiency in the water. This is the most common reason, but there are a few more causes for top-swimming that you should be aware of.

Swim Bladder Syndrome

The swim bladder is an organ in fish that helps them maintain balance and buoyancy. When the swim bladder is diseased, the fish will not be able to swim normally and thus you’ll see your fish leaning to one side or laying at the top or bottom of the tank. Other symptoms such as a bloated belly or bent spine may be apparent. Swim bladder disorder can be caused by a number of factors.

  • Excess air in your fish caused by gulping at the surface for food or oxygen can prevent the swim bladder from working properly.
  • Bacteria inside your tank can infect the swim bladder and lead it to become enlarged, swollen, and inflamed.
  • Low water temperature or sudden pressure change can put pressure on the organ.
  • Overfeeding will enlarge the stomach which also puts pressure on the swim bladder.

To prevent swim bladder disorder, keep the tank waters shallow enough as to not put too much pressure on your fish. Keep the water clean with a healthy but not too strong circulation, and make sure the temperature is between 78 and 80 degrees Fahrenheit. Experts recommend adding crushed green peas without skins to your feeding regimen.

Low Oxygen Levels

An oxygen deficient tank will drive fish towards the top where oxygen levels are higher. One cause of low oxygen levels would be stagnant water. If the pump is not strong enough, there is no way for the oxygen to be dispersed throughout the tank’s water and fish will struggle to breathe.

You also may need to change your filter or replace it with stronger one. Water is your fish’s oxygen source and habitat. If it’s dirty and poorly oxygenated, your fish will quite literally be suffocating and struggling to breathe. If you notice labored breathing and gulping, your fish is likely struggling to breathe.


Your aquarium is a community and each fish and object contributes to the ecosystem. Guppies may be stressed by overcrowding of fish and objects. Consider removing some decorations if space is tight.

Guppies are friendly and peaceful by nature. It’s thought that guppies seek to escape more aggressive fish by hiding at the top of the tank in avoidance. If the guppy is new to the tank they may be stressed from the environmental change and are trying to escape towards the top.

Incorrect Water pH and Quality

The ideal pH for guppies is between 7.0 and 7.2. They can withstand slight variations, but you need to be performing regular water changes and quality tests to ensure your guppies are not suffering. A high pH can be toxic and even fatal if left untreated.

Water Temperature

Guppies require a water temperature from 72 to 84 degrees. You should have a heater for your aquarium to maintain a constant healthy temperature. Water that is too warm can’t hold enough oxygen for guppies to thrive, sending them to the top where oxygen is always more abundant.

Water that’s too cold slows down metabolism, making fish tired and inactive. Keep in mind that other types of fish may prefer colder temperatures. It is crucial to do your research on what types of fish can be paired together comfortably.

When changing your tank’s water, make sure to change only a portion of the water at a time. This will reduce the amount of stress that cleanings cause, and keep important bacteria in the ecosystem rather than wiping it out. Regular cleanings are required for a healthy aquarium, but make sure to research the procedure beforehand.

Are Guppies Swimming to the Top because they’re Hungry?

Your guppies are most likely not swimming around the surface of the tank to look for food. In nature, food is not always thrown at them cleanly twice a day on surface level. Food can be found at any water level in the wild, so they will no be instinctively searching for a meal only on the surface.

It is recommended to feed guppies 2-3 times per day and to disperse the food around the tank. Make sure to vary their food options and mix in cooked and skinned green peas to help prevent swim bladder disorder. You can even add human foods like chopped kale, cucumbers, and apples to provide some extra nutrients.