Do fish need oxygen?

In this brief article, we will answer the question, “Do fish need oxygen?” and provide information on why fish can swim close to the water surface, how fish gets oxygen in an aquarium, what occurs in case of less oxygen as well as how to fix low oxygen levels in a tank.

Do fish need oxygen?

Yes, fish needs oxygen. Fish has gills that can help them in taking in oxygen. The gills of a fish is similar to the lungs of humans. The levels of oxygen in water are higher compared to the ones in the air.

The gills can take in oxygen after the oxygen is dissolved in water. The oxygen is taken through water by the fish whereas the carbon dioxide is released into the water. The oxygen enters the blood of the fish into other tissues of the body.

Why do some fish swim close to the water surface?

Fish like whales or dolphins are mammals. These mammals can have difficulty taking oxygen through water. As a result, they come over to the surface of the water and take in oxygen through the air. 

How do fish get oxygen in aquariums?

Fish can take in oxygen from water. However, when fish are kept in a tank, the oxygen can quickly get depleted. In such cases, the fish can come close to the water surface to take in oxygen.

Oxygen machines can be fitted into tanks to produce oxygen. However in case of a power outage, the survival of fish can depend on the size of the tank, the number of fish in a tank as well as the species of fish.

If there are too many fish in the tank, there can be very little oxygen left. An increase in temperature and salinity can also deplete oxygen.

The plants present in aquariums can also influence oxygen levels. If the plants have a shorter light period, there can be less oxygen present in the tank.

If the plants are exposed to more light, they can produce more oxygen because of photosynthesis. 

Apart from this, the presence of bacteria can influence oxygen levels. If there are too many bacteria in the tank, oxygen can get reduced.

What can occur if there is less oxygen in the tank?

When there is less oxygen in the tank, a fish can die or struggle to breathe air. The fish can start to push water out of their gills. This is the way they try to get oxygen.

Some fish come to the surface of the water to get oxygen. If you find your fish on the surface of the water, it is an indication of the oxygen levels being low. Sometimes, algae can produce oxygen in the tank.

This way, the fish might get a little bit of oxygen to breathe. However, algae can produce oxygen only during the day. 

However, too much oxygen in the tank is not suitable for the fish either. There is a risk of your fish developing gas bubble disease wherein there can be bubbles formed around the fish.

How can you fix oxygen levels in a tank?

  • Keep only one fish per gallon of water.
  • Higher water temperature can cause oxygen to sustain more in water. However, the water should not be too hot. You can reduce the temperature of the water using the water heater.

If you feel that the water temperature is increasing, you can also place a bag of ice cubes close to the tank. This can bring down the temperature of the water.

  • If your aquarium water is stagnant, the oxygen can deplete quickly. In such cases, you can install a filter to move the water a bit. 

Make sure to check whether the filter is clogged. If the filter is clogged, the water present in a tank would not move around. 

  • Clean the tank regularly. This is because excess bacterial growth can suck out oxygen from the tank. Make sure to clean them properly.
  • Increase the levels of light in the tank. If there are natural plants present in the tank, you can add a light or increase lighting levels in the tank.
  • Some chemicals added to the tank (to treat a fish suffering from disease) can reduce the oxygen levels. Make sure to agitate water more to increase its oxygen levels.
  • If you add new fish to the tank, make sure to gradually add them to tank. This can allow time for beneficial bacteria to gradually grow in a tank without oxygen depletion.

Conclusion

In this brief article, we have answered the question, “Do fish need oxygen?” and provided information on why fish can swim close to the water surface, how fish gets oxygen in an aquarium, what occurs in case of less oxygen as well as how to fix low oxygen levels in a tank.

Reference

https://kidadl.com/facts/do-fish-need-oxygen-here-s-what-low-oxygen-can-do-to-them

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