Top 8 Reasons Why Guppies Stay At The Top Of The Tank [+Fixes!]

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One of the many traits people love so much about Guppies is how lively they are inside a tank. But if a guppy tends to stick to the top of the tank only and they aren’t swimming around much, that’s an indication that something’s wrong. 

Guppies that gravitate towards the top of the tank are often looking for something, whether that be some oxygen or some nibbles. Your guppy might also be trying to tell you that there’s something about their tank conditions that isn’t suitable for them. If your guppy seems happy and you’ve been maintaining their tank appropriately, there may be no need to worry. 

The good news is that if your guppy is staying at the top of the aquarium or tank for concerning reasons, there are some easy fixes to bring your guppy back to happiness. 

#1. Your Guppies Are Trying To Breathe


CAUSE: If there are insufficient oxygen levels in your aquarium, your guppy could be struggling to get enough air. Typically, you’ll see physical symptoms that make it fairly obvious that this is the concern. While it’s true that guppies can breathe perfectly fine under water using their gills, if the water conditions aren’t adequate, there might not be enough oxygen for your guppy. 

Additionally, water tends to contain higher concentrations of oxygen towards the top of the tank. If it looks like your guppy is more frantic than usual or appears to be gasping for air, there’s a good chance that their fixation with the top of the tank is them trying to find clean oxygen to breathe. 

SOLUTION: An air pump can help ensure that oxygen is always circulating throughout the entire tank. Water needs to be circulating around the tank as well with at least a little bit of movement in order for oxygen to be able to move through water and make its way to your guppies and other fish.

Related: 7 Smart Ways To Aerate A Fish Tank Without A Pump!

Adding live aquatic plants also helps ensure the water has enough oxygen so guppies aren’t rushing to the surface in an effort to look for air to breathe. Furthermore, aquatic plants help to add extra filtration to the tank, helping to eliminate toxins in the water that could be impeding the oxygen supply. 

#2. The Tank Has Too Many Fish

CAUSE: Even though guppies are small, they like to have space to swim around. If a tank is too packed with fish your guppy might feel like it’s way too crowded and will attempt to find a spot for themselves. Guppies tend to get along with a variety of fish naturally, but that doesn’t always mean that companion fish will be nice to your guppies.

Sometimes, you might just have to reconfigure an aquarium to make some more space. This could involve redecorating to remove clutter as well as choosing different aquatic accessories that also function as hiding spots for fish who need some rest. If this doesn’t work, you might have to take more drastic measures. 

SOLUTION: If your fish aren’t getting along, there’s not much you can do to encourage this to change. You might have to make some changes to your aquarium. Unfortunately, transferring fish from one tank to another requires quite a few steps and takes some time. 

It could be a bit of a hassle, but it might be the only way for your guppies and the rest of your fish to feel safe and secure in their environment. It’s worth trying to reconfigure your tank in terms of accessories and plants before you try separating your fish. 

#3. The Water Isn’t Suitable 

CAUSE: Water quality is absolutely essential for keeping all fish happy and healthy. Fish have their preferences for how acidic or alkaline they like their water, what temperatures they prefer, and how temperate or calm they prefer their water. When the water isn’t to your guppy’s liking, they might stick to the top of the tank in an effort to get away from what’s bothering them. 

SOLUTION: Check your tank’s filtration system to see if it’s still functioning as it should be. It may need a replacement filter or the system itself might need to be upgraded. A water heater can help keep water at an appropriate temperature. You should also have a thermometer and check it frequently in case the temperature needs to be adjusted.

#4. Your Guppy is Sick 

CAUSE: There are a couple of potential illnesses that your guppy might be experiencing if they seem to just float around the top of the tank. If your guppy’s personality, activity level, or appetite seems to have changed and their water and tank conditions are good, your guppy might not be feeling well. 

There are some illnesses that guppies are more susceptible to. One such illness is swim bladder syndrome, which impacts their ability to pass gas and swim lower in the tank. Gill flukes can also impact the way your guppy acts and looks. Their gills will appear red and they will often gravitate towards the top of the tank seemingly gasping for air. 

SOLUTION: It can be difficult to pinpoint exactly what’s making your guppy sick which can be distressing. The first course of action is to make sure water is clean, the temperature is ideal, and test for any bacteria or contaminants in the water. 

If you’re still not sure what’s wrong, having a veterinarian help you diagnose the problem is highly recommended. When you’re able to isolate the cause, you can then create a specific treatment plan with a vet to get your guppy back to good health. 

#5. Your Guppies Are Hungry 

CAUSE: Even though guppies are small fish, they like to eat. Guppies are also smart fish that know that their best chance of getting food is by being close to the top of the tank where they know you drop food. Your guppies do eat some of the algae inside the tank naturally, but you also need to supplement their diet so that they’re getting enough nutrition. 

SOLUTION: This potential issue has a very simple solution. If you give your guppies some nibbles and they go back to acting the way they normally do, they were likely just hungry. You should also watch that none of your fish are fighting each other for food. 

Since guppies are so friendly, they won’t compete for food. They’ll just go without and end up getting sick due to inadequate nutrition. As such, you want to watch to make sure they get enough nibbles.

Check Out: How Long Can Guppies Go Without Food?

#6. You Recently Completed A Water Change

CAUSE: Water changes are essential to the health of everyone and everything in an aquarium. Guppies might seem to gravitate more towards the top of a tank for a few days after a water change. This is actually a normal behavior they exhibit and it’s nothing to be concerned about. 

Sudden changes in water, even if they’re good changes, can startle your fish temporarily. Doing a water change improperly might also stress out your fish. As long as your guppy gets back to their regular habits shortly after the water change is completed then you likely did just fine. 

SOLUTION: While you don’t want to ignore your guppy, you can rest assured that they are simply adapting to the water change. So long as they are behaving normally in every other way, you’ll just have to give it some time. Monitor your fish closely for a few days after a water change just in case. 

#7. Your Guppy is Stressed 

CAUSE: Stressed out fish tend to show behavioral changes. Stress can be very bad for fish and if it’s not taken care of, it could make your guppy more prone to illness. Many of the reasons for stress are because of the environment inside the tank, which could either be because of tankmates or because of water. 

SOLUTION: Trying to determine why your guppy is stressed can take some trial and error. Your first step is to test water to make sure there aren’t contaminants or inadequate water conditions. Substances like ammonia and nitrates can stress fish out and make them sick quickly if not taken care of. 

Setting up a tank at home needs to be done with a lot of forethought to avoid stress. Be sure your fish have adequate space and the mates you choose for your guppies all like the same water parameters. If any fish seem to be bullying your guppies, it might be time to start acclimating a new tank to separate your fish. 

#8. Your Guppy Prefers The Top of the Tank

CAUSE: Many guppy owners have noticed that their guppies enjoy swimming towards the top of the tank. This might be because of where other fish in the tank may be taking up space. It could also just be because of the way the aquarium is set up. 

As long as your guppy isn’t behaving abnormally, there’s no need to worry about their affinity for the top of the tank. 

SOLUTION: If you’re able to rule out illness, stress, water issues, or concerns about tank size or tank mates, let your guppy enjoy swimming at the top of the tank. It may just be where they’re happiest, and a happy guppy is the ultimate goal. 

Wrapping Up

Guppies are one of the easiest fish to care for which adds to their popularity amongst aquarium owners. That said, guppies still have their needs and their preferences and will do their best to communicate in their own ways if something is wrong. One way they might show you something’s wrong is by staying at the top of the tank unless that’s a part of their regular routine.  

Every fish owner knows how crucial it is to set up a tank environment specific to their fish of choice and those conditions need to be maintained. Doing so for your guppies can help to prevent most of the above mentioned issues that could have them acting differently.