Angelfish may prefer the top of the tank, but staying there could mean your tank is overcrowded, there may not be enough dissolved oxygen, your angelfish could be carrying a disease, the water quality may be poor, or the temperature may be too cold.
Because all angelfish have different personalities and preferences, they could have some strange behavior. It is important to note that if angelfish stays at the top of the tank for extended periods, it could mean something is wrong, and you’ll need to fix it as soon as possible.
Why Do Angelfish Stay At The Top Of The Tank?
Usually, angelfish will happily glide through the water and hang out at all the different depths of your aquarium.
While some fish varieties will mostly prefer to dwell close to the bottom, others will prefer to spend their days in the upper or middle sections of the aquarium.
Angelfish are the best of both worlds, as they will spend a lot of time exploring the entire tank. If you’ve recently bought angelfish, you may be worried if you notice these strange behaviors.
Under normal circumstances, you’ll see your angelfish swim mostly in the middle of the tank, but it could be concerning when you notice them staying at the top. If this behavior is followed by gasping, there is something wrong.
Angelfish Staying At The Top Due To Overcrowding
If you have a community aquarium, too many fish may pollute the tank water. The rule of thumb for most freshwater fish would be one gallon per inch of adult fish.
However, remember that some fish are larger-bodied than others, and some will be more taxing on the aquarium’s environment than others.
Use this rule only as a guideline, and be sure to calculate the adult sizes of the fish in your aquarium.
Angelfish Staying At The Top Due To Lack Of Oxygen
The second important factor to consider is if your angelfish is breathing properly. Observe their behavior and ask yourself questions like, “does the angelfish seem to be gasping when spending time at the top of the tank?”
If you see these gasping movements, your angelfish are likely struggling to get oxygen. Angelfish will use dissolved oxygen in the water so they will breathe properly.
When there is insufficient dissolved oxygen in their aquarium, it will make it difficult for them to breathe, resulting in them moving to the top part of the tank to get sufficient amounts of oxygen.
As dissolved oxygen will be more at the top, your angelfish will exhibit this behavior to find a spot with a higher concentration.
If this is the issue in your aquarium, you may be happy to hear that it’s a quick and easy fix, and you won’t have to stand by and watch your angelfish struggling to breathe.
You can purchase an air stone or an air pump that you can add to your tank, which will oxygenate the tank water more, making it easier for your angelfish to breathe.
Angelfish Staying At The Top Due To Disease
If your angelfish carries disease, they can become so sick that they are forced to stay at the top of the tank.
Your two primary concerns should be Swim Bladder Disease and Gills Infections, as these two diseases are quite common amongst angelfish.
Swim Bladder Infection is the most common problem, and it will affect your angelfish’s ability to swim.
If their swim bladder’s functions deteriorate, your angelfish’s ability to move through the aquarium will suffer.
Although many people expect this condition to keep angelfish at the bottom of the aquarium, or cause them to swim upside down, sideways, or vertically, they don’t realize that it could also cause them to float to the top parts of the tank.
Your second concern would be a gills infection. Some infections and diseases will attack your angelfish’s gills, compromising their breathing abilities.
In this case, you will notice your angelfish rushing to the top of the tank in search to find some of the oxygen-rich water.
However, this won’t be helpful, as they need to absorb the oxygen through their gills. If fungi, gill flukes, or similar have attacked the gills, they will not be able to breathe as they should.
Angelfish Staying At The Top Due To Poor Water Quality
If you suspect your water quality may be the problem, you can start your troubleshooting by performing a water test.
A water test will rule out any problems with water quality, including ammonia, nitrite, salinity levels, and pH levels.
You can also try to determine some other reasons why your aquarium’s water may be of poor quality.
If the water in your aquarium seems to have a cloudy or polluted appearance, it may be possible that you are overfeeding your fish, or there may be a deceased fish.
Whatever the case, you will need to replace as much water as is needed to bring your aquarium’s water conditions to a healthy balance.
Angelfish Staying At The Top Due To Incorrect Temperatures
If your aquarium’s water is not at the right temperature, it will significantly impact your angelfish.
You must try to keep the tank water warm enough for your angelfish. Ideally, an aquarium with angelfish present will need to be kept between 76 degrees and 84 degrees.
While angelfish can survive in a temperature slightly cooler or hotter, it would be best to stay in this range as closely as possible.
Your angelfish will be much healthier if their water temperature is correct, and if they are forced to live in too cold water for extended periods, they may not live very long and healthy lives.
It would be good to note that angelfish will not respond well to sudden temperature fluctuations, and they will start acting strangely if the temperature swings too fast.
It might be best to get a heater for your aquarium to keep these things from happening.
Although angelfish are hardy, they are quite sensitive when their aquarium isn’t kept in the ideal circumstances for them to thrive.
While it may be possible that your angelfish prefer staying at the top, you should always monitor them to ensure this behavior doesn’t continue; if it does, some troubleshooting may be required to ensure their health!