what are the signs of low oxygen level in fish tank? know before its too late

Check Our Quick Stories

Why Your Fish Is Sitting Bottom of the Tank?

Why My Betta Isn’t Moving Or Swimming? Top 7 Reasons

Why Is Your Discus Turning Black?

Why Are Lionfish Harmful to Coral Areas & Reefs?

What Should Be The Ideal Depth of A Koi Pond?

Low oxygen level in the aquarium is the most common problem of fish keepers. Now if you don’t know the signs of low oxygen level at your aquarium, then a great loss can happen for you.

So here I’m gonna discuss some signs which you should remember while fish keeping.

Without wasting much time let’s deep dive into the topic

What are the signs of low oxygen level at aquarium?

You can’t get the signs if you casually look at your aquarium but if you look carefully, then you may see these signs

Fishes gasp at the surface of water
Labored breathing
Fish movement will be less
Fish will not eat normally

Now let’s discuss these points

Fishes gasp at the surface of water

There are some fishes like dwarf gourami, paradise fish, Betta etc. take oxygen from the surface to the water level but this will be a serious point when you will see that all of your fishes are trying to take oxygen from water surface. This will be a sign of less oxygen level at your aquarium.

Labored breathing

In general way the fishes use their gill to take oxygen to take breath. There is nothing wrong with it. But when you will see that the gills of your fishes are moving more than normal, then it may cause to low oxygen level at your aquarium.

When there is less oxygen in the water, then fishes try to take more oxygen from water by moving it faster than normal time.

Fish movement will be less

When you will see that all of your fish movement become slower than normal, then there could be a chance of less oxygen at your aquarium.

It happens because when fishes can’t able to get enough oxygen from water, then they lose their energy to move

Note – body cells use the oxygen to breathe to get energy from the food. This process is called cellular respiration

Fish will not eat normally

If oxygen level is low, then fish will not eat frequently. But it may be confusing because if the stomach of your fishes is full then they will not eat also.

But here you need to apply common sense to understand the matter because all of your fish eat food at a certain level. Now if they don’t eat food like normally, then there may be a problem regarding the air issue.

I guess you have got an awareness of the signs of low oxygen levels at your aquarium. Right? Now that is not enough I think because at this moment you need to know why did this happen to your aquarium otherwise it will happen surely in future.

So let’s know what the main causes of low oxygen level of aquarium are

What are the main causes of low oxygen level at your aquarium?

Temperature increase

You should know that the solubility of oxygen at water is inversely proportional to the temperature according to the source. That means if the surrounding temperature increases then the oxygen level of water body will drop and then it will help to create a low oxygen level at aquarium.

Not only on temperature, but the solubility of oxygen depends upon the salinity of water also. That’s why saltwater aquarium base more oxygen level than a freshwater aquarium.

Infograph

Note –At room temperature 21°C dissolved oxygen (DO) level is 8mg/L at 100% air saturation.

Stagnancy of water

If the surface of water is not movable then the chances of oxygen dissolve at water will be less. The more movement will happen, the more oxygen will dissolve into water according to the source.. So you need to add filter always to make water surface movable.

Overstocking of fishes

If you put more and more fish relatively smaller aquarium then a low oxygen level may occur for it. You need to maintain a good ratio of it otherwise all of your fishes will face this problem and you may see a great loss for you after a while.

The surface area of water is less

DO is directly proportional to the surface of water. That means if the top of your aquarium is narrow then the surface of water will be less and DO will be less also than a Normal aquarium. So you have to check this issue also.

Low lights at aquarium

Low light can be a factor in the low oxygen level of aquarium. If your aquarium is planted then those plants will start taking oxygen and will release carbon dioxide just because of low light. But if you can provide enough lights then this issue will not happen

Now the next question you should know how to get rid of thing issue if it happens anytime.

How you can increase the oxygen level of aquarium?

Add cool water

Adding a bucket of cool water will increase the oxygen level of water at aquarium. You should know cool water carry more dissolved oxygen than relatively warmer water. So if you put cool water in aquarium then it will increase oxygen level definitely.

Not only that when you put water in aquarium then it will create a movement of water surface and more oxygen will mix up with water due to this reason

So here you can oxygenate your aquarium water by two ways basically.

Note – Add or exchange water of aquarium twice or thrice in a week. This will be best

Add aquatic plant

Adding aquatic plants in your aquarium will be a good decision to oxygenate your aquarium. But make sure that your aquarium has enough lights because plants will not exhale carbon dioxide instead of oxygen if it doesn’t start photosynthesis.

Note –Anacharis and Java fern will be good selection of live plants for aquarium

Add good filter

The filter is needed for an aquarium and here are the causes

A good filter helps to oxygenate the water
Filter helps to remove poisonous chemicals like nitrate and ammonium
It helps to remove biological wastage & floating particulates
Extra foods are filtered by a good filter
Helps to keep clean and the fresh water of an aquarium

Note – canister filter is the best filter in recent times for aquarium

Use wider aquarium

A wider aquarium will be the best for you if you are just starting out now.

Here is why

As I said earlier the surface area of water is directly proportional to the dissolved oxygen in the water. So if you want to keep your fishes healthy then you must you wider aquarium which will help you to give a better surface area of water than a narrow one.

If you use a narrow but deep aquarium then it will carry more water than a shallow one and in this case, oxygen will be much less into the water of that aquarium. This is unhealthy for a crowded aquarium.

Now you must use a shallow one because a shallow aquarium will help you to clean it easily and a low maintenance cost is required for this type of aquarium.

Note –22”x12”x13” size will be the best for freshwater fish

36”x18”x12” size will be the best for saltwater fish

Add air stones

Air stones or air bubblers a great thing to use in aquariums to increase the oxygen level in the water. This helps to make very good vertical water movement. So oxygen dissolves automatically with the water. But if you have a good filter then you don’t need this.

Use chemical in the water

Chemicals can be used as oxygen increaser also. Here you can use calcium peroxide (CaO2) as a chemical in the water.

According to research calcium peroxide is a great chemical that increases oxygen level without harming the living organisms except for algae. Fish can live easily if you mix it with your aquarium water. Micro-organisms will not be affected by it also.

Chemical reaction with water

CaO2+H2O > Ca(OH)2+H2O2

H2O2> O2+H2O

Note – You should use 20 gram calcium peroxide to 37.5 Litre water to oxygenate it according to the research

Final thoughts

Signs of low oxygen are not noticeable. So you have to keep eye on your aquarium. This will be a big issue for you but here I’ve given solutions also. If you apply these solutions, then you will not face any trouble regarding this issue.

So best of luck & happy fishkeeping 🐟